tests/test_field.py

@@ -5,21 +5,33 @@ import sympy as sp
 import pystencils as ps
 from pystencils import TypedSymbol
 from pystencils.typing import create_type
-from pystencils.field import Field, FieldType, layout_string_to_tuple
+from pystencils.field import Field, FieldType, layout_string_to_tuple, spatial_layout_string_to_tuple
 
 
 def test_field_basic():
-    f = Field.create_generic('f', spatial_dimensions=2)
+    f = Field.create_generic("f", spatial_dimensions=2)
     assert FieldType.is_generic(f)
-    assert f['E'] == f[1, 0]
-    assert f['N'] == f[0, 1]
-    assert '_' in f.center._latex('dummy')
-
-    assert f.index_to_physical(index_coordinates=sp.Matrix([0, 0]), staggered=False)[0] == 0
-    assert f.index_to_physical(index_coordinates=sp.Matrix([0, 0]), staggered=False)[1] == 0
-
-    assert f.physical_to_index(physical_coordinates=sp.Matrix([0, 0]), staggered=False)[0] == 0
-    assert f.physical_to_index(physical_coordinates=sp.Matrix([0, 0]), staggered=False)[1] == 0
+    assert f["E"] == f[1, 0]
+    assert f["N"] == f[0, 1]
+    assert "_" in f.center._latex("dummy")
+
+    assert (
+        f.index_to_physical(index_coordinates=sp.Matrix([0, 0]), staggered=False)[0]
+        == 0
+    )
+    assert (
+        f.index_to_physical(index_coordinates=sp.Matrix([0, 0]), staggered=False)[1]
+        == 0
+    )
+
+    assert (
+        f.physical_to_index(physical_coordinates=sp.Matrix([0, 0]), staggered=False)[0]
+        == 0
+    )
+    assert (
+        f.physical_to_index(physical_coordinates=sp.Matrix([0, 0]), staggered=False)[1]
+        == 0
+    )
 
     f1 = f.new_field_with_different_name("f1")
     assert f1.ndim == f.ndim
@@ -28,7 +40,7 @@ def test_field_basic():
     fixed = ps.fields("f(5, 5) : double[20, 20]")
     assert fixed.neighbor_vector((1, 1)).shape == (5, 5)
 
-    f = Field.create_fixed_size('f', (10, 10), strides=(80, 8), dtype=np.float64)
+    f = Field.create_fixed_size("f", (10, 10), strides=(80, 8), dtype=np.float64)
     assert f.spatial_strides == (10, 1)
     assert f.index_strides == ()
     assert f.center_vector == sp.Matrix([f.center])
@@ -37,20 +49,21 @@ def test_field_basic():
     assert f1.ndim == f.ndim
     assert f1.values_per_cell() == f.values_per_cell()
 
-    f = Field.create_fixed_size('f', (8, 8, 2, 2), index_dimensions=2)
-    assert f.center_vector == sp.Matrix([[f(0, 0), f(0, 1)],
-                                         [f(1, 0), f(1, 1)]])
+    f = Field.create_fixed_size("f", (8, 8, 2, 2), index_dimensions=2)
+    assert f.center_vector == sp.Matrix([[f(0, 0), f(0, 1)], [f(1, 0), f(1, 1)]])
     field_access = f[1, 1]
     assert field_access.nr_of_coordinates == 2
-    assert field_access.offset_name == 'NE'
+    assert field_access.offset_name == "NE"
     neighbor = field_access.neighbor(coord_id=0, offset=-2)
     assert neighbor.offsets == (-1, 1)
-    assert '_' in neighbor._latex('dummy')
+    assert "_" in neighbor._latex("dummy")
 
-    f = Field.create_fixed_size('f', (8, 8, 2, 2, 2), index_dimensions=3)
-    assert f.center_vector == sp.Array([[[f(i, j, k) for k in range(2)] for j in range(2)] for i in range(2)])
+    f = Field.create_fixed_size("f", (8, 8, 2, 2, 2), index_dimensions=3)
+    assert f.center_vector == sp.Array(
+        [[[f(i, j, k) for k in range(2)] for j in range(2)] for i in range(2)]
+    )
 
-    f = Field.create_generic('f', spatial_dimensions=5, index_dimensions=2)
+    f = Field.create_generic("f", spatial_dimensions=5, index_dimensions=2)
     field_access = f[1, -1, 2, -3, 0](1, 0)
     assert field_access.offsets == (1, -1, 2, -3, 0)
     assert field_access.index == (1, 0)
@@ -60,61 +73,71 @@ def test_error_handling():
     struct_dtype = np.dtype([('a', np.int32), ('b', np.float64), ('c', np.uint32)])
     Field.create_generic('f', spatial_dimensions=2, index_dimensions=0, dtype=struct_dtype)
     with pytest.raises(ValueError) as e:
-        Field.create_generic('f', spatial_dimensions=2, index_dimensions=1, dtype=struct_dtype)
-    assert 'index dimension' in str(e.value)
+        Field.create_generic(
+            "f", spatial_dimensions=2, index_dimensions=1, dtype=struct_dtype
+        )
+    assert "index dimension" in str(e.value)
 
-    arr = np.array([[[(1,)*3, (2,)*3, (3,)*3]]*2], dtype=struct_dtype)
-    Field.create_from_numpy_array('f', arr, index_dimensions=0)
+    arr = np.array([[[(1,) * 3, (2,) * 3, (3,) * 3]] * 2], dtype=struct_dtype)
+    Field.create_from_numpy_array("f", arr, index_dimensions=0)
     with pytest.raises(ValueError) as e:
-        Field.create_from_numpy_array('f', arr, index_dimensions=1)
-    assert 'Structured arrays' in str(e.value)
+        Field.create_from_numpy_array("f", arr, index_dimensions=1)
+    assert "Structured arrays" in str(e.value)
 
     arr = np.zeros([3, 3, 3])
-    Field.create_from_numpy_array('f', arr, index_dimensions=2)
+    Field.create_from_numpy_array("f", arr, index_dimensions=2)
     with pytest.raises(ValueError) as e:
-        Field.create_from_numpy_array('f', arr, index_dimensions=3)
-    assert 'Too many' in str(e.value)
+        Field.create_from_numpy_array("f", arr, index_dimensions=3)
+    assert "Too many" in str(e.value)
 
-    Field.create_fixed_size('f', (3, 2, 4), index_dimensions=0, dtype=struct_dtype, layout='reverse_numpy')
+    Field.create_fixed_size(
+        "f", (3, 2, 4), index_dimensions=0, dtype=struct_dtype, layout="reverse_numpy"
+    )
     with pytest.raises(ValueError) as e:
-        Field.create_fixed_size('f', (3, 2, 4), index_dimensions=1, dtype=struct_dtype, layout='reverse_numpy')
-    assert 'Structured arrays' in str(e.value)
-
-    f = Field.create_fixed_size('f', (10, 10))
+        Field.create_fixed_size(
+            "f",
+            (3, 2, 4),
+            index_dimensions=1,
+            dtype=struct_dtype,
+            layout="reverse_numpy",
+        )
+    assert "Structured arrays" in str(e.value)
+
+    f = Field.create_fixed_size("f", (10, 10))
     with pytest.raises(ValueError) as e:
         f[1]
-    assert 'Wrong number of spatial indices' in str(e.value)
+    assert "Wrong number of spatial indices" in str(e.value)
 
-    f = Field.create_generic('f', spatial_dimensions=2, index_shape=(3,))
+    f = Field.create_generic("f", spatial_dimensions=2, index_shape=(3,))
     with pytest.raises(ValueError) as e:
         f(3)
-    assert 'out of bounds' in str(e.value)
+    assert "out of bounds" in str(e.value)
 
-    f = Field.create_fixed_size('f', (10, 10, 3, 4), index_dimensions=2)
+    f = Field.create_fixed_size("f", (10, 10, 3, 4), index_dimensions=2)
     with pytest.raises(ValueError) as e:
         f(3, 0)
-    assert 'out of bounds' in str(e.value)
+    assert "out of bounds" in str(e.value)
 
     with pytest.raises(ValueError) as e:
         f(1, 0)(1, 0)
-    assert 'Indexing an already indexed' in str(e.value)
+    assert "Indexing an already indexed" in str(e.value)
 
     with pytest.raises(ValueError) as e:
         f(1)
-    assert 'Wrong number of indices' in str(e.value)
+    assert "Wrong number of indices" in str(e.value)
 
     with pytest.raises(ValueError) as e:
-        Field.create_generic('f', spatial_dimensions=2, layout='wrong')
-    assert 'Unknown layout descriptor' in str(e.value)
+        Field.create_generic("f", spatial_dimensions=2, layout="wrong")
+    assert "Unknown layout descriptor" in str(e.value)
 
-    assert layout_string_to_tuple('fzyx', dim=4) == (3, 2, 1, 0)
+    assert layout_string_to_tuple("fzyx", dim=4) == (3, 2, 1, 0)
     with pytest.raises(ValueError) as e:
-        layout_string_to_tuple('wrong', dim=4)
-    assert 'Unknown layout descriptor' in str(e.value)
+        layout_string_to_tuple("wrong", dim=4)
+    assert "Unknown layout descriptor" in str(e.value)
 
 
 def test_decorator_scoping():
-    dst = ps.fields('dst : double[2D]')
+    dst = ps.fields("dst : double[2D]")
 
     def f1():
         a = sp.Symbol("a")
@@ -134,7 +157,7 @@ def test_decorator_scoping():
 
 
 def test_string_creation():
-    x, y, z = ps.fields('  x(4),    y(3,5) z : double[  3,  47]')
+    x, y, z = ps.fields("  x(4),    y(3,5) z : double[  3,  47]")
     assert x.index_shape == (4,)
     assert y.index_shape == (3, 5)
     assert z.spatial_shape == (3, 47)
@@ -142,19 +165,85 @@ def test_string_creation():
 
 def test_itemsize():
 
-    x = ps.fields('x: float32[1d]')
-    y = ps.fields('y:  float64[2d]')
-    i = ps.fields('i:  int16[1d]')
+    x = ps.fields("x: float32[1d]")
+    y = ps.fields("y:  float64[2d]")
+    i = ps.fields("i:  int16[1d]")
 
     assert x.itemsize == 4
     assert y.itemsize == 8
     assert i.itemsize == 2
 
 
+def test_spatial_memory_layout_descriptors():
+    assert (
+        spatial_layout_string_to_tuple("AoS", 3)
+        == spatial_layout_string_to_tuple("aos", 3)
+        == spatial_layout_string_to_tuple("ZYXF", 3)
+        == spatial_layout_string_to_tuple("zyxf", 3)
+        == (2, 1, 0)
+    )
+    assert (
+        spatial_layout_string_to_tuple("SoA", 3)
+        == spatial_layout_string_to_tuple("soa", 3)
+        == spatial_layout_string_to_tuple("FZYX", 3)
+        == spatial_layout_string_to_tuple("fzyx", 3)
+        == spatial_layout_string_to_tuple("f", 3)
+        == spatial_layout_string_to_tuple("F", 3)
+        == (2, 1, 0)
+    )
+    assert (
+        spatial_layout_string_to_tuple("c", 3)
+        == spatial_layout_string_to_tuple("C", 3)
+        == (0, 1, 2)
+    )
+
+    assert spatial_layout_string_to_tuple("C", 5) == (0, 1, 2, 3, 4)
+
+    with pytest.raises(ValueError):
+        spatial_layout_string_to_tuple("aos", -1)
+
+    with pytest.raises(ValueError):
+        spatial_layout_string_to_tuple("aos", 4)
+
+
+def test_memory_layout_descriptors():
+    assert (
+        layout_string_to_tuple("AoS", 4)
+        == layout_string_to_tuple("aos", 4)
+        == layout_string_to_tuple("ZYXF", 4)
+        == layout_string_to_tuple("zyxf", 4)
+        == (2, 1, 0, 3)
+    )
+    assert (
+        layout_string_to_tuple("SoA", 4)
+        == layout_string_to_tuple("soa", 4)
+        == layout_string_to_tuple("FZYX", 4)
+        == layout_string_to_tuple("fzyx", 4)
+        == layout_string_to_tuple("f", 4)
+        == layout_string_to_tuple("F", 4)
+        == (3, 2, 1, 0)
+    )
+    assert (
+        layout_string_to_tuple("c", 4)
+        == layout_string_to_tuple("C", 4)
+        == (0, 1, 2, 3)
+    )
+
+    assert layout_string_to_tuple("C", 5) == (0, 1, 2, 3, 4)
+
+    with pytest.raises(ValueError):
+        layout_string_to_tuple("aos", -1)
+
+    with pytest.raises(ValueError):
+        layout_string_to_tuple("aos", 5)
+
+
 def test_staggered():
 
     # D2Q5
-    j1, j2, j3 = ps.fields('j1(2), j2(2,2), j3(2,2,2) : double[2D]', field_type=FieldType.STAGGERED)
+    j1, j2, j3 = ps.fields(
+        "j1(2), j2(2,2), j3(2,2,2) : double[2D]", field_type=FieldType.STAGGERED
+    )
 
     assert j1[0, 1](1) == j1.staggered_access((0, sp.Rational(1, 2)))
     assert j1[0, 1](1) == j1.staggered_access(np.array((0, sp.Rational(1, 2))))
@@ -163,7 +252,7 @@ def test_staggered():
     assert j1[0, 1](1) == j1.staggered_access("N")
     assert j1[0, 0](1) == j1.staggered_access("S")
     assert j1.staggered_vector_access("N") == sp.Matrix([j1.staggered_access("N")])
-    assert j1.staggered_stencil_name == 'D2Q5'
+    assert j1.staggered_stencil_name == "D2Q5"
 
     assert j1.physical_coordinates[0] == TypedSymbol("ctr_0", create_type("int"), nonnegative=True)
     assert j1.physical_coordinates[1] == TypedSymbol("ctr_1", create_type("int"), nonnegative=True)
@@ -176,28 +265,40 @@ def test_staggered():
 
     assert j2[0, 1](1, 1) == j2.staggered_access((0, sp.Rational(1, 2)), 1)
     assert j2[0, 1](1, 1) == j2.staggered_access("N", 1)
-    assert j2.staggered_vector_access("N") == sp.Matrix([j2.staggered_access("N", 0), j2.staggered_access("N", 1)])
+    assert j2.staggered_vector_access("N") == sp.Matrix(
+        [j2.staggered_access("N", 0), j2.staggered_access("N", 1)]
+    )
 
     assert j3[0, 1](1, 1, 1) == j3.staggered_access((0, sp.Rational(1, 2)), (1, 1))
     assert j3[0, 1](1, 1, 1) == j3.staggered_access("N", (1, 1))
-    assert j3.staggered_vector_access("N") == sp.Matrix([[j3.staggered_access("N", (i, j))
-                                                        for j in range(2)] for i in range(2)])
+    assert j3.staggered_vector_access("N") == sp.Matrix(
+        [[j3.staggered_access("N", (i, j)) for j in range(2)] for i in range(2)]
+    )
 
     # D2Q9
-    k1, k2 = ps.fields('k1(4), k2(2) : double[2D]', field_type=FieldType.STAGGERED)
+    k1, k2 = ps.fields("k1(4), k2(2) : double[2D]", field_type=FieldType.STAGGERED)
 
     assert k1[1, 1](2) == k1.staggered_access("NE")
     assert k1[0, 0](2) == k1.staggered_access("SW")
     assert k1[0, 0](3) == k1.staggered_access("NW")
-    
+
     a = k1.staggered_access("NE")
-    assert a._staggered_offset(a.offsets, a.index[0]) == [sp.Rational(1, 2), sp.Rational(1, 2)]
+    assert a._staggered_offset(a.offsets, a.index[0]) == [
+        sp.Rational(1, 2),
+        sp.Rational(1, 2),
+    ]
     a = k1.staggered_access("SW")
-    assert a._staggered_offset(a.offsets, a.index[0]) == [sp.Rational(-1, 2), sp.Rational(-1, 2)]
+    assert a._staggered_offset(a.offsets, a.index[0]) == [
+        sp.Rational(-1, 2),
+        sp.Rational(-1, 2),
+    ]
     a = k1.staggered_access("NW")
-    assert a._staggered_offset(a.offsets, a.index[0]) == [sp.Rational(-1, 2), sp.Rational(1, 2)]
+    assert a._staggered_offset(a.offsets, a.index[0]) == [
+        sp.Rational(-1, 2),
+        sp.Rational(1, 2),
+    ]
 
     # sign reversed when using as flux field
-    r = ps.fields('r(2) : double[2D]', field_type=FieldType.STAGGERED_FLUX)
+    r = ps.fields("r(2) : double[2D]", field_type=FieldType.STAGGERED_FLUX)
     assert r[0, 0](0) == r.staggered_access("W")
     assert -r[1, 0](0) == r.staggered_access("E")

tests/test_gpu.py

 import pytest
 
 import numpy as np
-import cupy as cp
 import sympy as sp
+import math
 from scipy.ndimage import convolve
 
-from pystencils import Assignment, Field, fields, CreateKernelConfig, create_kernel, Target
+from pystencils import Assignment, Field, fields, CreateKernelConfig, create_kernel, Target, get_code_str
 from pystencils.gpu import BlockIndexing
 from pystencils.simp import sympy_cse_on_assignment_list
 from pystencils.slicing import add_ghost_layers, make_slice, remove_ghost_layers, normalize_slice
 
 try:
-    import cupy
-    device_numbers = range(cupy.cuda.runtime.getDeviceCount())
+    import cupy as cp
+    device_numbers = range(cp.cuda.runtime.getDeviceCount())
 except ImportError:
     device_numbers = []
+    cp = None
 
 
 def test_averaging_kernel():
+    pytest.importorskip('cupy')
     size = (40, 55)
     src_arr = np.random.rand(*size)
     src_arr = add_ghost_layers(src_arr)
@@ -44,6 +46,7 @@ def test_averaging_kernel():
 
 
 def test_variable_sized_fields():
+    pytest.importorskip('cupy')
     src_field = Field.create_generic('src', spatial_dimensions=2)
     dst_field = Field.create_generic('dst', spatial_dimensions=2)
 
@@ -71,6 +74,7 @@ def test_variable_sized_fields():
 
 
 def test_multiple_index_dimensions():
+    pytest.importorskip('cupy')
     """Sums along the last axis of a numpy array"""
     src_size = (7, 6, 4)
     dst_size = src_size[:2]
@@ -103,6 +107,7 @@ def test_multiple_index_dimensions():
 
 
 def test_ghost_layer():
+    pytest.importorskip('cupy')
     size = (6, 5)
     src_arr = np.ones(size)
     dst_arr = np.zeros_like(src_arr)
@@ -127,6 +132,7 @@ def test_ghost_layer():
 
 
 def test_setting_value():
+    pytest.importorskip('cupy')
     arr_cpu = np.arange(25, dtype=np.float64).reshape(5, 5)
     arr_gpu = cp.asarray(arr_cpu)
 
@@ -143,6 +149,7 @@ def test_setting_value():
 
 
 def test_periodicity():
+    pytest.importorskip('cupy')
     from pystencils.gpu.periodicity import get_periodic_boundary_functor as periodic_gpu
     from pystencils.slicing import get_periodic_boundary_functor as periodic_cpu
 
@@ -163,6 +170,7 @@ def test_periodicity():
 
 @pytest.mark.parametrize("device_number", device_numbers)
 def test_block_indexing(device_number):
+    pytest.importorskip('cupy')
     f = fields("f: [3D]")
     s = normalize_slice(make_slice[:, :, :], f.spatial_shape)
     bi = BlockIndexing(s, f.layout, block_size=(16, 8, 2),
@@ -195,6 +203,7 @@ def test_block_indexing(device_number):
 @pytest.mark.parametrize('layout', ("C", "F"))
 @pytest.mark.parametrize('shape', ((5, 5, 5, 5), (3, 17, 387, 4), (23, 44, 21, 11)))
 def test_four_dimensional_kernel(gpu_indexing, layout, shape):
+    pytest.importorskip('cupy')
     n_elements = np.prod(shape)
 
     arr_cpu = np.arange(n_elements, dtype=np.float64).reshape(shape, order=layout)
@@ -210,3 +219,39 @@ def test_four_dimensional_kernel(gpu_indexing, layout, shape):
 
     kernel(f=arr_gpu, value=np.float64(42.0))
     np.testing.assert_equal(arr_gpu.get(), np.ones(shape) * 42.0)
+
+
+@pytest.mark.parametrize('start', (1, 5))
+@pytest.mark.parametrize('end', (-1, -2, -3, -4))
+@pytest.mark.parametrize('step', (1, 2, 3, 4))
+@pytest.mark.parametrize('shape', ([55, 60], [77, 101, 80], [44, 64, 66]))
+def test_guards_with_iteration_slices(start, end, step, shape):
+    iter_slice = tuple([slice(start, end, step)] * len(shape))
+
+    kernel_config_gpu = CreateKernelConfig(target=Target.GPU, iteration_slice=iter_slice)
+    field_1 = fields(f"f(1) : double{list(shape)}")
+    assignment = Assignment(field_1.center, 1)
+    ast = create_kernel(assignment, config=kernel_config_gpu)
+    code_str = get_code_str(ast)
+
+    test_strings = list()
+    iteration_ranges = list()
+    for i, s in enumerate(iter_slice):
+        e = ((shape[i] + end) - s.start) / s.step
+        e = math.ceil(e) + s.start
+        test_strings.append(f"{s.start} < {e}")
+
+        a = s.start
+        counter = 0
+        while a < e:
+            a += 1
+            counter += 1
+        iteration_ranges.append(counter)
+
+    # check if the expected if statement is in the GPU code
+    for s in test_strings:
+        assert s in code_str
+
+    # check if these bounds lead to same lengths as the range function would produce
+    for i in range(len(iter_slice)):
+        assert iteration_ranges[i] == len(range(iter_slice[i].start, shape[i] + end, iter_slice[i].step))

tests/test_indexed_kernels.py

@@ -64,15 +64,15 @@ def test_indexed_domain_kernel(index_size, array_size, target, dtype):
     src = sp.IndexedBase(TypedSymbol(f"_data_{f.name}", dtype=const_pointer_type), shape=index_src)
     dst = sp.IndexedBase(TypedSymbol(f"_data_{g.name}", dtype=pointer_type), shape=index_dst)
 
-    update_rule = [ps.Assignment(FieldPointerSymbol("f", dtype, const=True), src[index]),
-                   ps.Assignment(FieldPointerSymbol("g", dtype, const=False), dst[index]),
+    update_rule = [ps.Assignment(FieldPointerSymbol("f", dtype, const=True), src[index + 1]),
+                   ps.Assignment(FieldPointerSymbol("g", dtype, const=False), dst[index + 1]),
                    ps.Assignment(g.center, f.center)]
 
     ast = ps.create_kernel(update_rule, target=target)
 
     code = ps.get_code_str(ast)
-    assert f"const {dtype.c_name} * RESTRICT _data_f = (({dtype.c_name} * RESTRICT const)(_data_f[index]));" in code
-    assert f"{dtype.c_name} * RESTRICT  _data_g = (({dtype.c_name} * RESTRICT )(_data_g[index]));" in code
+    assert f"const {dtype.c_name} * RESTRICT _data_f = (({dtype.c_name} * RESTRICT const)(_data_f[index + 1]));" in code
+    assert f"{dtype.c_name} * RESTRICT  _data_g = (({dtype.c_name} * RESTRICT )(_data_g[index + 1]));" in code
 
     if target == Target.CPU:
         assert code.count("for") == f.spatial_dimensions + 1

tests/test_jupyter_extensions.ipynb

 %% Cell type:code id: tags:
 
 ``` python
 from pystencils.session import *
 ```
 
 %% Cell type:code id: tags:
 
 ``` python
 dh = ps.create_data_handling(domain_size=(256, 256), periodicity=True)
 c_field = dh.add_array('c')
 dh.fill("c", 0.0, ghost_layers=True)
 ```
 
 %% Cell type:code id: tags:
 
 ``` python
 for x in range(129):
     for y in range(258):
         dh.cpu_arrays['c'][x, y] = 1.0
 ```
 
 %% Cell type:code id: tags:
 
 ``` python
 plt.scalar_field(dh.cpu_arrays["c"])
 ```
 
 %% Output
 
-    <matplotlib.image.AxesImage at 0x7fcb7d253710>
+    <matplotlib.image.AxesImage at 0x117081c10>
 
-
+
 
 %% Cell type:code id: tags:
 
 ``` python
 ur = ps.Assignment(c_field[0, 0], c_field[1, 0])
-ast = ps.create_kernel(ur, target=dh.default_target, cpu_openmp=True)
+config = ps.CreateKernelConfig(target=dh.default_target, cpu_openmp=False, skip_independence_check=True)
+ast = ps.create_kernel(ur, config=config)
 kernel = ast.compile()
 ```
 
 %% Cell type:code id: tags:
 
 ``` python
 c_sync = dh.synchronization_function_cpu(['c'])
 ```
 
 %% Cell type:code id: tags:
 
 ``` python
 def timeloop(steps=10):
     for i in range(steps):
         c_sync()
         dh.run_kernel(kernel)
     return dh.gather_array('c')
 ```
 
 %% Cell type:code id: tags:
 
 ``` python
 ps.jupyter.set_display_mode('video')
 ```
 
 %% Cell type:code id: tags:
 
 ``` python
 ani = ps.plot.scalar_field_animation(timeloop, rescale=True, frames=12)
 ps.jupyter.display_animation(ani)
 ```
 
 %% Output
 
     <IPython.core.display.HTML object>
 
 %% Cell type:code id: tags:
 
 ``` python
 ps.jupyter.set_display_mode('image_update')
 ```
 
 %% Cell type:code id: tags:
 
 ``` python
 ani = ps.plot.scalar_field_animation(timeloop, rescale=True, frames=12)
 ps.jupyter.display_animation(ani)
 ```
 
 %% Output
 
-
+
 
 %% Cell type:code id: tags:
 
 ``` python
 def grid_update_function(image):
     for i in range(40):
         c_sync()
         dh.run_kernel(kernel)
     return dh.gather_array('c')
 ```
 
 %% Cell type:code id: tags:
 
 ``` python
 animation = ps.jupyter.make_imshow_animation(dh.cpu_arrays["c"], grid_update_function, frames=300)
 ```
 
 %% Output
 
-
+
 
 %% Cell type:code id: tags:
 
 ``` python
 ps.jupyter.set_display_mode("video")
 ps.jupyter.set_display_mode("window")
 ps.jupyter.set_display_mode("image_update")
 ps.jupyter.activate_ipython()
 ```
+
+%% Output
+
+    ---------------------------------------------------------------------------
+    ImportError                               Traceback (most recent call last)
+Cell     In[14], line 2
+          1 ps.jupyter.set_display_mode("video")
+    ----> 2 ps.jupyter.set_display_mode("window")
+          3 ps.jupyter.set_display_mode("image_update")
+          4 ps.jupyter.activate_ipython()
+File     ~/pystencils/pystencils/src/pystencils/jupyter.py:115, in set_display_mode(mode)
+        113     display_animation_func = display_as_html_video
+        114 elif animation_display_mode == 'window':
+    --> 115     ipython.magic("matplotlib qt")
+        116     display_animation_func = display_in_extra_window
+        117 elif animation_display_mode == 'image_update':
+File     /opt/local/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/IPython/core/interactiveshell.py:2539, in InteractiveShell.magic(self, arg_s)
+       2537 magic_name, _, magic_arg_s = arg_s.partition(' ')
+       2538 magic_name = magic_name.lstrip(prefilter.ESC_MAGIC)
+    -> 2539 return self.run_line_magic(magic_name, magic_arg_s, _stack_depth=2)
+File     /opt/local/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/IPython/core/interactiveshell.py:2417, in InteractiveShell.run_line_magic(self, magic_name, line, _stack_depth)
+       2415     kwargs['local_ns'] = self.get_local_scope(stack_depth)
+       2416 with self.builtin_trap:
+    -> 2417     result = fn(*args, **kwargs)
+       2419 # The code below prevents the output from being displayed
+       2420 # when using magics with decodator @output_can_be_silenced
+       2421 # when the last Python token in the expression is a ';'.
+       2422 if getattr(fn, magic.MAGIC_OUTPUT_CAN_BE_SILENCED, False):
+File     /opt/local/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/IPython/core/magics/pylab.py:99, in PylabMagics.matplotlib(self, line)
+         97     print("Available matplotlib backends: %s" % backends_list)
+         98 else:
+    ---> 99     gui, backend = self.shell.enable_matplotlib(args.gui.lower() if isinstance(args.gui, str) else args.gui)
+        100     self._show_matplotlib_backend(args.gui, backend)
+File     /opt/local/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/IPython/core/interactiveshell.py:3603, in InteractiveShell.enable_matplotlib(self, gui)
+       3599         print('Warning: Cannot change to a different GUI toolkit: %s.'
+       3600                 ' Using %s instead.' % (gui, self.pylab_gui_select))
+       3601         gui, backend = pt.find_gui_and_backend(self.pylab_gui_select)
+    -> 3603 pt.activate_matplotlib(backend)
+       3604 configure_inline_support(self, backend)
+       3606 # Now we must activate the gui pylab wants to use, and fix %run to take
+       3607 # plot updates into account
+File     /opt/local/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/IPython/core/pylabtools.py:360, in activate_matplotlib(backend)
+        355 # Due to circular imports, pyplot may be only partially initialised
+        356 # when this function runs.
+        357 # So avoid needing matplotlib attribute-lookup to access pyplot.
+        358 from matplotlib import pyplot as plt
+    --> 360 plt.switch_backend(backend)
+        362 plt.show._needmain = False
+        363 # We need to detect at runtime whether show() is called by the user.
+        364 # For this, we wrap it into a decorator which adds a 'called' flag.
+File     /opt/local/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/matplotlib/pyplot.py:271, in switch_backend(newbackend)
+        268 # have to escape the switch on access logic
+        269 old_backend = dict.__getitem__(rcParams, 'backend')
+    --> 271 backend_mod = importlib.import_module(
+        272     cbook._backend_module_name(newbackend))
+        274 required_framework = _get_required_interactive_framework(backend_mod)
+        275 if required_framework is not None:
+File     /opt/local/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/importlib/__init__.py:126, in import_module(name, package)
+        124             break
+        125         level += 1
+    --> 126 return _bootstrap._gcd_import(name[level:], package, level)
+File     <frozen importlib._bootstrap>:1204, in _gcd_import(name, package, level)
+File     <frozen importlib._bootstrap>:1176, in _find_and_load(name, import_)
+File     <frozen importlib._bootstrap>:1147, in _find_and_load_unlocked(name, import_)
+File     <frozen importlib._bootstrap>:690, in _load_unlocked(spec)
+File     <frozen importlib._bootstrap_external>:940, in exec_module(self, module)
+File     <frozen importlib._bootstrap>:241, in _call_with_frames_removed(f, *args, **kwds)
+File     /opt/local/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/matplotlib/backends/backend_qt5agg.py:7
+          4 from .. import backends
+          6 backends._QT_FORCE_QT5_BINDING = True
+    ----> 7 from .backend_qtagg import (    # noqa: F401, E402 # pylint: disable=W0611
+          8     _BackendQTAgg, FigureCanvasQTAgg, FigureManagerQT, NavigationToolbar2QT,
+          9     FigureCanvasAgg, FigureCanvasQT)
+         12 @_BackendQTAgg.export
+         13 class _BackendQT5Agg(_BackendQTAgg):
+         14     pass
+File     /opt/local/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/matplotlib/backends/backend_qtagg.py:9
+          5 import ctypes
+          7 from matplotlib.transforms import Bbox
+    ----> 9 from .qt_compat import QT_API, _enum
+         10 from .backend_agg import FigureCanvasAgg
+         11 from .backend_qt import QtCore, QtGui, _BackendQT, FigureCanvasQT
+File     /opt/local/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/matplotlib/backends/qt_compat.py:135
+        133         break
+        134     else:
+    --> 135         raise ImportError(
+        136             "Failed to import any of the following Qt binding modules: {}"
+        137             .format(", ".join(_ETS.values())))
+        138 else:  # We should not get there.
+        139     raise AssertionError(f"Unexpected QT_API: {QT_API}")
+    ImportError: Failed to import any of the following Qt binding modules: PyQt6, PySide6, PyQt5, PySide2

tests/test_math_functions.py

@@ -39,7 +39,7 @@ def test_two_arguments(dtype, func, target):
 
 
 @pytest.mark.parametrize('dtype', ["float64", "float32"])
-@pytest.mark.parametrize('func', [sp.sin, sp.cos, sp.sinh, sp.cosh, sp.atan])
+@pytest.mark.parametrize('func', [sp.sin, sp.cos, sp.sinh, sp.cosh, sp.atan, sp.floor, sp.ceiling])
 @pytest.mark.parametrize('target', [ps.Target.CPU, ps.Target.GPU])
 def test_single_arguments(dtype, func, target):
     if target == ps.Target.GPU:
@@ -58,7 +58,8 @@ def test_single_arguments(dtype, func, target):
     ast = ps.create_kernel(up, config=config)
     code = ps.get_code_str(ast)
     if dtype == 'float32':
-        assert func.__name__.lower() in code
+        func_name = func.__name__.lower() if func is not sp.ceiling else "ceil"
+        assert func_name in code
     kernel = ast.compile()
 
     dh.all_to_gpu()

tests/test_phasefield_dentritic_3D.ipynb

 %% Cell type:code id: tags:
 
 ``` python
 import pytest
 pytest.importorskip('cupy')
 ```
 
 %% Output
 
-    <module 'cupy' from '/home/markus/.local/lib/python3.11/site-packages/cupy/__init__.py'>
+    <module 'cupy' from '/home/markus/Python311/lib/python3.11/site-packages/cupy/__init__.py'>
 
 %% Cell type:code id: tags:
 
 ``` python
 from pystencils.session import *
 sp.init_printing()
 frac = sp.Rational
 ```
 
 %% Cell type:markdown id: tags:
 
 # Phase-field simulation of dentritic solidification in 3D
 
 This notebook tests the model presented in the dentritic growth tutorial in 3D.
 
 %% Cell type:code id: tags:
 
 ``` python
 target = ps.Target.GPU
 gpu = target == ps.Target.GPU
 domain_size = (25, 25, 25) if 'is_test_run' in globals() else (300, 300, 300)
 
 dh = ps.create_data_handling(domain_size=domain_size, periodicity=True, default_target=target)
 φ_field = dh.add_array('phi', latex_name='φ')
+φ_field_tmp = dh.add_array('phi_tmp', latex_name='φ_tmp')
 φ_delta_field = dh.add_array('phidelta', latex_name='φ_D')
 t_field = dh.add_array('T')
+t_field_tmp = dh.add_array('T_tmp')
 ```
 
 %% Cell type:code id: tags:
 
 ``` python
 ε, m, δ, j, θzero, α, γ, Teq, κ, τ = sp.symbols("ε m δ j θ_0 α γ T_eq κ τ")
 εb = sp.Symbol("\\bar{\\epsilon}")
 discretize = ps.fd.Discretization2ndOrder(dx=0.03, dt=1e-5)
 
 φ = φ_field.center
 T = t_field.center
 d = ps.fd.Diff
 
 def f(φ, m):
     return φ**4 / 4 - (frac(1, 2) - m/3) * φ**3 + (frac(1,4)-m/2)*φ**2
 
 
 
 bulk_free_energy_density = f(φ, m)
 interface_free_energy_density = ε ** 2 / 2 * (d(φ, 0) ** 2 + d(φ, 1) ** 2 + d(φ, 2) ** 2)
 ```
 
 %% Cell type:markdown id: tags:
 
 Here comes the major change, that has to be made for the 3D model: $\epsilon$ depends on the interface normal, which can not be computed simply as atan() as in the 2D case
 
 %% Cell type:code id: tags:
 
 ``` python
 n = sp.Matrix([d(φ, i) for i in range(3)])
 nLen = sp.sqrt(sum(n_i**2 for n_i in n))
 n = n / nLen
 nVal = sum(n_i**4 for n_i in n)
 σ = δ * nVal
 
 εVal = εb * (1 + σ)
 εVal
 ```
 
 %% Output
 
     $\displaystyle \bar{\epsilon} \left(δ \left(\frac{{\partial_{0} {φ}_{(0,0,0)}}^{4}}{\left({\partial_{0} {φ}_{(0,0,0)}}^{2} + {\partial_{1} {φ}_{(0,0,0)}}^{2} + {\partial_{2} {φ}_{(0,0,0)}}^{2}\right)^{2}} + \frac{{\partial_{1} {φ}_{(0,0,0)}}^{4}}{\left({\partial_{0} {φ}_{(0,0,0)}}^{2} + {\partial_{1} {φ}_{(0,0,0)}}^{2} + {\partial_{2} {φ}_{(0,0,0)}}^{2}\right)^{2}} + \frac{{\partial_{2} {φ}_{(0,0,0)}}^{4}}{\left({\partial_{0} {φ}_{(0,0,0)}}^{2} + {\partial_{1} {φ}_{(0,0,0)}}^{2} + {\partial_{2} {φ}_{(0,0,0)}}^{2}\right)^{2}}\right) + 1\right)$
-                   ⎛  ⎛                            4                                               4                                               4                ⎞    ⎞
-                   ⎜  ⎜                 D(φ[0,0,0])                                     D(φ[0,0,0])                                     D(φ[0,0,0])                 ⎟    ⎟
-    \bar{\epsilon}⋅⎜δ⋅⎜───────────────────────────────────────────── + ───────────────────────────────────────────── + ─────────────────────────────────────────────⎟ + 1⎟
-                   ⎜  ⎜                                            2                                               2                                               2⎟    ⎟
-                   ⎜  ⎜⎛           2              2              2⎞    ⎛           2              2              2⎞    ⎛           2              2              2⎞ ⎟    ⎟
-                   ⎝  ⎝⎝D(φ[0,0,0])  + D(φ[0,0,0])  + D(φ[0,0,0]) ⎠    ⎝D(φ[0,0,0])  + D(φ[0,0,0])  + D(φ[0,0,0]) ⎠    ⎝D(φ[0,0,0])  + D(φ[0,0,0])  + D(φ[0,0,0]) ⎠ ⎠    ⎠
+                   ⎛  ⎛                            4
+                   ⎜  ⎜                 D(φ[0,0,0])
+    \bar{\epsilon}⋅⎜δ⋅⎜───────────────────────────────────────────── + ───────────
+                   ⎜  ⎜                                            2
+                   ⎜  ⎜⎛           2              2              2⎞    ⎛
+                   ⎝  ⎝⎝D(φ[0,0,0])  + D(φ[0,0,0])  + D(φ[0,0,0]) ⎠    ⎝D(φ[0,0,0]
+    
+                     4                                               4
+          D(φ[0,0,0])                                     D(φ[0,0,0])
+    ────────────────────────────────── + ─────────────────────────────────────────
+                                     2
+     2              2              2⎞    ⎛           2              2
+    )  + D(φ[0,0,0])  + D(φ[0,0,0]) ⎠    ⎝D(φ[0,0,0])  + D(φ[0,0,0])  + D(φ[0,0,0]
+    
+        ⎞    ⎞
+        ⎟    ⎟
+    ────⎟ + 1⎟
+       2⎟    ⎟
+     2⎞ ⎟    ⎟
+    ) ⎠ ⎠    ⎠
 
 %% Cell type:code id: tags:
 
 ``` python
 def m_func(temperature):
     return (α / sp.pi) * sp.atan(γ * (Teq - temperature))
 ```
 
 %% Cell type:code id: tags:
 
 ``` python
 substitutions = {m: m_func(T),
                  ε: εVal}
 
 fe_i = interface_free_energy_density.subs(substitutions)
 fe_b = bulk_free_energy_density.subs(substitutions)
 
 μ_if = ps.fd.expand_diff_full(ps.fd.functional_derivative(fe_i, φ), functions=[φ])
 μ_b = ps.fd.expand_diff_full(ps.fd.functional_derivative(fe_b, φ), functions=[φ])
 ```
 
 %% Cell type:code id: tags:
 
 ``` python
 dF_dφ = μ_b + sp.Piecewise((μ_if, nLen**2 > 1e-10), (0, True))
 ```
 
 %% Cell type:code id: tags:
 
 ``` python
 parameters = {
     τ: 0.0003,
     κ: 1.8,
     εb: 0.01,
     δ: 0.3,
     γ: 10,
     j: 6,
     α: 0.9,
     Teq: 1.0,
     θzero: 0.2,
     sp.pi: sp.pi.evalf()
 }
 parameters
 ```
 
 %% Output
 
-
+
     $\displaystyle \left\{ \pi : 3.14159265358979, \  T_{eq} : 1.0, \  \bar{\epsilon} : 0.01, \  j : 6, \  α : 0.9, \  γ : 10, \  δ : 0.3, \  θ_{0} : 0.2, \  κ : 1.8, \  τ : 0.0003\right\}$
-    {π: 3.14159265358979, T_eq: 1.0, \bar{\epsilon}: 0.01, j: 6, α: 0.9, γ: 10, δ: 0.3, θ₀: 0.2, κ: 1.8, τ: 0.0003}
+    {π: 3.14159265358979, T_eq: 1.0, \bar{\epsilon}: 0.01, j: 6, α: 0.9, γ: 10, δ:
+     0.3, θ₀: 0.2, κ: 1.8, τ: 0.0003}
 
 %% Cell type:code id: tags:
 
 ``` python
 dφ_dt = - dF_dφ / τ
 assignments = [
     ps.Assignment(φ_delta_field.center, discretize(dφ_dt.subs(parameters))),
 ]
 φEqs = ps.simp.sympy_cse_on_assignment_list(assignments)
-φEqs.append(ps.Assignment(φ, discretize(ps.fd.transient(φ) - φ_delta_field.center)))
+φEqs.append(ps.Assignment(φ_field_tmp.center, discretize(ps.fd.transient(φ) - φ_delta_field.center)))
 
 
 temperatureEvolution = -ps.fd.transient(T) + ps.fd.diffusion(T, 1) + κ * φ_delta_field.center
 temperatureEqs = [
-    ps.Assignment(T, discretize(temperatureEvolution.subs(parameters)))
+    ps.Assignment(t_field_tmp.center, discretize(temperatureEvolution.subs(parameters)))
 ]
 ```
 
 %% Cell type:code id: tags:
 
 ``` python
-temperatureEqs
-```
-
-%% Output
-
-    $\displaystyle \left[ {T}_{(0,0,0)} \leftarrow 0.0111111111111111 {T}_{(0,0,-1)} + 0.933333333333333 {T}_{(0,0,0)} + 0.0111111111111111 {T}_{(1,0,0)} + 0.0111111111111111 {T}_{(0,1,0)} + 0.0111111111111111 {T}_{(0,-1,0)} + 0.0111111111111111 {T}_{(0,0,1)} + 0.0111111111111111 {T}_{(-1,0,0)} + 1.8 \cdot 10^{-5} {φ_D}_{(0,0,0)}\right]$
-    [T_C := 0.0111111111111111⋅T_B + 0.933333333333333⋅T_C + 0.0111111111111111⋅T_E + 0.0111111111111111⋅T_N + 0.0111111111111111⋅T_S + 0.0111111111111111⋅T_T + 0.0111111111111111⋅T_
-    W + 1.8e-5⋅phidelta_C]
-
-%% Cell type:code id: tags:
-
-``` python
 φ_kernel = ps.create_kernel(φEqs, cpu_openmp=4, target=target).compile()
 temperatureKernel = ps.create_kernel(temperatureEqs, cpu_openmp=4, target=target).compile()
 ```
 
 %% Cell type:code id: tags:
 
 ``` python
 def time_loop(steps):
     φ_sync = dh.synchronization_function(['phi'], target=target)
     temperature_sync = dh.synchronization_function(['T'], target=target)
     dh.all_to_gpu()
     for t in range(steps):
         φ_sync()
         dh.run_kernel(φ_kernel)
         temperature_sync()
         dh.run_kernel(temperatureKernel)
+        dh.swap(φ_field.name, φ_field_tmp.name)
+        dh.swap(t_field.name, t_field_tmp.name)
     dh.all_to_cpu()
 
 
 def init(nucleus_size=np.sqrt(5)):
     for b in dh.iterate():
         x, y, z = b.cell_index_arrays
         x, y, z = x - b.shape[0] // 2, y - b.shape[1] // 2, z - b.shape[2] // 2
         b['phi'].fill(0)
         b['phi'][(x ** 2 + y ** 2 + z ** 2) < nucleus_size ** 2] = 1.0
         b['T'].fill(0.0)
 
 
 def plot(slice_obj=ps.make_slice[:, :, 0.5]):
     plt.subplot(1, 3, 1)
     plt.scalar_field(dh.gather_array('phi', slice_obj).squeeze())
     plt.title("φ")
     plt.colorbar()
     plt.subplot(1, 3, 2)
     plt.title("T")
     plt.scalar_field(dh.gather_array('T', slice_obj).squeeze())
     plt.colorbar()
     plt.subplot(1, 3, 3)
     plt.title("∂φ")
     plt.scalar_field(dh.gather_array('phidelta', slice_obj).squeeze())
     plt.colorbar()
 ```
 
 %% Cell type:code id: tags:
 
 ``` python
 init()
 plot()
 print(dh)
 ```
 
 %% Output
 
         Name|      Inner (min/max)|     WithGl (min/max)
     ----------------------------------------------------
            T|            (  0,  0)|            (  0,  0)
+       T_tmp|            (  0,  0)|            (  0,  0)
          phi|            (  0,  1)|            (  0,  1)
+     phi_tmp|            (  0,  0)|            (  0,  0)
     phidelta|            (  0,  0)|            (  0,  0)
     
 
-
+
 
 %% Cell type:code id: tags:
 
 ``` python
 if 'is_test_run' in globals():
     time_loop(2)
     assert np.isfinite(dh.max('phi'))
     assert np.isfinite(dh.max('T'))
     assert np.isfinite(dh.max('phidelta'))
 else:
     from time import perf_counter
     vtk_writer = dh.create_vtk_writer('dentritic_growth_large', ['phi'])
     last = perf_counter()
-    for i in range(300):
+    for i in range(4):
         time_loop(100)
         vtk_writer(i)
         print("Step ", i, perf_counter() - last, dh.max('phi'))
         last = perf_counter()
 ```
 
 %% Output
 
-    Step  0 25.45903586700115 0.9934522628963286
-    Step  1 17.733385490000728 0.993928549434581
-    Step  2 17.385464679000506 0.9969817492516411
-    Step  3 17.73187294499985 0.9987018046573852
-    Step  4 17.42424472499988 0.9994581962161123
-    Step  5 17.39850756800115 0.9997730200431632
-    Step  6 17.38586500100064 0.9999032282027154
-    Step  7 17.41260802599936 0.9999573480152241
-    Step  8 17.873442951999095 0.9999802946360343
-    Step  9 17.04619025899956 0.9999955995645813
-    Step  10 17.099138269000832 0.9999996727969152
-    Step  11 17.099542428999484 0.999999973143393
-    Step  12 17.139662244000647 0.999999997546683
-    Step  13 17.218893876999573 0.9999999997490552
-    Step  14 17.084921174000556 0.999999999971159
-    Step  15 17.033554589999767 0.9999999999962744
-    Step  16 17.010074742000143 0.9999999999994603
-    Step  17 17.104563296001288 0.9999999999999127
-    Step  18 17.021247803000733 0.9999999999999842
-    Step  19 17.07957060999979 0.9999999999999966
-    Step  20 17.05240749100085 0.9999999999999966
-    Step  21 17.00356302900036 0.9999999999999966
-    Step  22 17.1113736719999 0.9999999999999966
-    Step  23 17.013587127999926 0.9999999999999966
-    Step  24 17.004048287999467 0.9999999999999966
-    Step  25 17.01311813599932 0.9999999999999966
-    Step  26 17.018968939000843 0.9999999999999966
-    Step  27 17.01230432599914 0.9999999999999966
-    Step  28 17.016388629001085 0.9999999999999966
-    Step  29 17.036423421999643 0.9999999999999966
-    Step  30 17.013809308999043 0.9999999999999966
-    Step  31 17.02102562500113 0.9999999999999966
-    Step  32 17.125694684000337 0.9999999999999966
-    Step  33 17.018816687999788 0.9999999999999966
-    Step  34 17.033273111001108 0.9999999999999966
-    Step  35 17.031105800999285 0.9999999999999966
-    Step  36 17.344186886000898 0.9999999999999966
-    Step  37 17.00491729500027 0.9999999999999966
-    Step  38 17.044662663000054 0.9999999999999966
-    Step  39 17.01994404600009 0.9999999999999966
-    Step  40 17.01687352800036 0.9999999999999966
-    Step  41 17.03885115400044 0.9999999999999966
-    Step  42 17.025812523999775 0.9999999999999966
-    Step  43 17.029889327999626 0.9999999999999966
-    Step  44 17.065132745001392 0.9999999999999966
-    Step  45 17.03455267100071 0.9999999999999966
-    Step  46 17.042484248999244 0.9999999999999966
-    Step  47 17.135204002001046 0.9999999999999966
-    Step  48 17.049361208000846 0.9999999999999966
-    Step  49 17.051931253001385 0.9999999999999966
-    Step  50 17.05464122400008 0.9999999999999966
-    Step  51 17.042147963999014 0.9999999999999966
-    Step  52 17.066642416000832 0.9999999999999966
-    Step  53 17.0870322819992 0.9999999999999966
-    Step  54 17.071626777000347 0.9999999999999966
-    Step  55 17.11173596700064 0.9999999999999966
-    Step  56 17.18877132200032 0.9999999999999966
-    Step  57 17.154270471000928 0.9999999999999966
-    Step  58 17.672991446001106 0.9999999999999966
-    Step  59 17.674105590998806 0.9999999999999966
-    Step  60 17.347509929999433 0.9999999999999966
-    Step  61 17.54230526399988 0.9999999999999966
-    Step  62 17.694092154999453 0.9999999999999966
-    Step  63 17.531714112999907 0.9999999999999966
-    Step  64 17.98786205900069 0.9999999999999966
-    Step  65 17.59379430700028 0.9999999999999966
-    Step  66 17.496220975999677 0.9999999999999966
-    Step  67 17.61460809500022 0.9999999999999966
-    Step  68 17.81554028100072 0.9999999999999966
-    Step  69 17.50470085699999 0.9999999999999966
-    Step  70 18.22215127399977 0.9999999999999966
-    Step  71 17.95782054099982 0.9999999999999966
-    Step  72 18.02512274399851 0.9999999999999966
-    Step  73 17.519333276000907 0.9999999999999966
-    Step  74 18.148525913999038 0.9999999999999966
-    Step  75 17.768654807998246 0.9999999999999966
-    Step  76 17.68822824000017 0.9999999999999966
-    Step  77 17.630756663000284 0.9999999999999966
-    Step  78 17.73377000599976 0.9999999999999966
-    Step  79 17.553744683998957 0.9999999999999966
-    Step  80 17.616365314001087 0.9999999999999966
-    Step  81 17.520774246000656 0.9999999999999966
-    Step  82 17.824773792999622 0.9999999999999966
-    Step  83 18.162243766000756 0.9999999999999966
-    Step  84 17.59411170199928 0.9999999999999966
-    Step  85 17.78331206599978 0.9999999999999966
-    Step  86 18.16322874999969 0.9999999999999966
-    Step  87 17.877422854000542 0.9999999999999966
-    Step  88 17.723775387999922 0.9999999999999966
-    Step  89 17.93192093200014 0.9999999999999966
-    Step  90 18.18813704400054 0.9999999999999966
-    Step  91 17.924124131999633 0.9999999999999966
-    Step  92 17.7537402930011 0.9999999999999966
-    Step  93 18.066451909000534 0.9999999999999966
-    Step  94 18.1830705400007 0.9999999999999966
-    Step  95 18.144785267999396 0.9999999999999966
-    Step  96 17.771601014001135 0.9999999999999966
-    Step  97 18.371283865000805 0.9999999999999966
-    Step  98 18.569847105998633 0.9999999999999966
-    Step  99 18.27999508600078 0.9999999999999966
-    Step  100 17.876706947999992 0.9999999999999966
-    Step  101 18.362252414000977 0.9999999999999966
-    Step  102 18.184471571999893 0.9999999999999966
-    Step  103 17.953990222000357 0.9999999999999966
-    Step  104 18.139474450999842 0.9999999999999966
-    Step  105 17.951657051999064 0.9999999999999966
-    Step  106 17.9079576109998 0.9999999999999966
-    Step  107 17.87303800600057 0.9999999999999966
-    Step  108 17.93147389799924 0.9999999999999966
-    Step  109 18.11586603000069 0.9999999999999966
-    Step  110 17.81402047099982 0.9999999999999966
-    Step  111 18.042384932999994 0.9999999999999966
-    Step  112 18.28486302300007 0.9999999999999966
-    Step  113 18.207277753999733 0.9999999999999966
-    Step  114 17.95677446300033 0.9999999999999966
-    Step  115 18.060943858001338 0.9999999999999966
-    Step  116 18.289367157000015 0.9999999999999966
-    Step  117 17.892628915000387 0.9999999999999966
-    Step  118 17.864017376999982 0.9999999999999966
-    Step  119 18.149063675000434 0.9999999999999966
-    Step  120 18.52748107499974 0.9999999999999966
-    Step  121 18.263750603000517 0.9999999999999966
-    Step  122 18.062445188999845 0.9999999999999966
-    Step  123 18.676733229000092 0.9999999999999966
-    Step  124 17.94438390400137 0.9999999999999966
-    Step  125 18.117840117000014 0.9999999999999966
-    Step  126 18.08436953599994 0.9999999999999966
-    Step  127 17.971794098000828 0.9999999999999966
-    Step  128 18.37189302399929 0.9999999999999966
-    Step  129 18.186950645000252 0.9999999999999966
-    Step  130 18.30828943600136 0.9999999999999966
-    Step  131 18.53486498699931 0.9999999999999966
-    Step  132 18.302330796001115 0.9999999999999966
-    Step  133 18.28120723899883 0.9999999999999966
-    Step  134 18.4264274319994 0.9999999999999966
-    Step  135 18.156916502000968 0.9999999999999966
-    Step  136 18.33176715799891 0.9999999999999966
-    Step  137 18.704046654000194 0.9999999999999966
-    Step  138 18.061599176000527 0.9999999999999966
-    Step  139 18.313615737000873 0.9999999999999966
-    Step  140 19.13900512299915 0.9999999999999966
-    Step  141 18.634621335999327 0.9999999999999966
-    Step  142 18.48925181300001 0.9999999999999966
-    Step  143 18.603877730000022 0.9999999999999966
-    Step  144 18.455599974000506 0.9999999999999966
-    Step  145 18.61112040399894 0.9999999999999966
-    Step  146 18.832362896999257 0.9999999999999966
-    Step  147 18.292130691001148 0.9999999999999966
-    Step  148 18.38444646700009 0.9999999999999966
-    Step  149 18.14168985700053 0.9999999999999966
-    Step  150 18.834586269000283 0.9999999999999966
-    Step  151 18.90085793199978 0.9999999999999966
-    Step  152 18.301890503000322 0.9999999999999966
-    Step  153 18.99428056400029 0.9999999999999966
-    Step  154 18.442107730001226 0.9999999999999966
-    Step  155 18.12089733100038 0.9999999999999966
-    Step  156 18.185502423999424 0.9999999999999966
-    Step  157 18.189794200001415 0.9999999999999966
+    Step  0 19.713090835999992 1.0
+    Step  1 19.673075279000045 1.0
+    Step  2 19.696444219 1.0
+    Step  3 19.752472744999977 1.0

tests/test_random.py

@@ -32,7 +32,7 @@ if get_compiler_config()['os'] == 'windows':
 def test_rng(target, rng, precision, dtype, t=124, offsets=(0, 0), keys=(0, 0), offset_values=None):
     if target == Target.GPU:
         pytest.importorskip('cupy')
-    if instruction_sets and {'neon', 'sve', 'vsx', 'rvv'}.intersection(instruction_sets) and rng == 'aesni':
+    if instruction_sets and {'neon', 'sve', 'sve2', 'sme', 'vsx', 'rvv'}.intersection(instruction_sets) and rng == 'aesni':
         pytest.xfail('AES not yet implemented for this architecture')
     if rng == 'aesni' and len(keys) == 2:
         keys *= 2
@@ -122,7 +122,7 @@ def test_rng_offsets(kind, vectorized):
 @pytest.mark.parametrize('rng', ('philox', 'aesni'))
 @pytest.mark.parametrize('precision,dtype', (('float', 'float'), ('double', 'double')))
 def test_rng_vectorized(target, rng, precision, dtype, t=130, offsets=(1, 3), keys=(0, 0), offset_values=None):
-    if (target in ['neon', 'vsx', 'rvv'] or target.startswith('sve')) and rng == 'aesni':
+    if (target in ['neon', 'vsx', 'rvv', 'sme'] or target.startswith('sve')) and rng == 'aesni':
         pytest.xfail('AES not yet implemented for this architecture')
     cpu_vectorize_info = {'assume_inner_stride_one': True, 'assume_aligned': True, 'instruction_set': target}
 

tests/test_simplifications.py

@@ -146,6 +146,16 @@ def test_add_subexpressions_for_field_reads():
     assert isinstance(ac3.subexpressions[0].lhs, TypedSymbol)
     assert ac3.subexpressions[0].lhs.dtype == BasicType("float32")
 
+    # added check for early out of add_subexpressions_for_field_reads is no fields appear on the rhs (See #92)
+    main = [Assignment(s[0, 0](0), 3.0),
+            Assignment(s[0, 0](1), 4.0)]
+
+    ac4 = AssignmentCollection(main, subexpressions)
+    assert len(ac4.subexpressions) == 0
+    ac5 = add_subexpressions_for_field_reads(ac4)
+    assert ac5 is not None
+    assert ac4 is ac5
+
 
 @pytest.mark.parametrize('target', (ps.Target.CPU, ps.Target.GPU))
 @pytest.mark.parametrize('dtype', ('float32', 'float64'))

tests/test_sliced_iteration.py

 import numpy as np
 import sympy as sp
+import pytest
 
-from pystencils import Assignment, Field, TypedSymbol, create_kernel, make_slice
+from pystencils import (
+    Assignment,
+    Field,
+    TypedSymbol,
+    create_kernel,
+    make_slice,
+    Target,
+    create_data_handling,
+)
 from pystencils.simp import sympy_cse_on_assignment_list
 
 
-def test_sliced_iteration():
+@pytest.mark.parametrize("target", [Target.CPU, Target.GPU])
+def test_sliced_iteration(target):
+    if target == Target.GPU:
+        pytest.importorskip("cupy")
+
     size = (4, 4)
-    src_arr = np.ones(size)
-    dst_arr = np.zeros_like(src_arr)
-    src_field = Field.create_from_numpy_array('src', src_arr)
-    dst_field = Field.create_from_numpy_array('dst', dst_arr)
+
+    dh = create_data_handling(size, default_target=target, default_ghost_layers=0)
+
+    src_field = dh.add_array("src", 1)
+    dst_field = dh.add_array("dst", 1)
+
+    dh.fill(src_field.name, 1.0, ghost_layers=True)
+    dh.fill(dst_field.name, 0.0, ghost_layers=True)
 
     a, b = sp.symbols("a b")
-    update_rule = Assignment(dst_field[0, 0],
-                             (a * src_field[0, 1] + a * src_field[0, -1] +
-                              b * src_field[1, 0] + b * src_field[-1, 0]) / 4)
+    update_rule = Assignment(
+        dst_field[0, 0],
+        (
+            a * src_field[0, 1]
+            + a * src_field[0, -1]
+            + b * src_field[1, 0]
+            + b * src_field[-1, 0]
+        )
+        / 4,
+    )
+
+    s = make_slice[1:3, 1]
+    kernel = create_kernel(
+        sympy_cse_on_assignment_list([update_rule]), iteration_slice=s, target=target
+    ).compile()
+
+    if target == Target.GPU:
+        dh.all_to_gpu()
+
+    dh.run_kernel(kernel, a=1.0, b=1.0)
+
+    if target == Target.GPU:
+        dh.all_to_cpu()
+
+    expected_result = np.zeros(size)
+    expected_result[1:3, 1] = 1
+    np.testing.assert_almost_equal(dh.gather_array(dst_field.name), expected_result)
+
+
+@pytest.mark.parametrize("target", [Target.CPU, Target.GPU])
+def test_symbols_in_slice(target):
+    if target == Target.GPU:
+        pytest.xfail("Iteration slices including arbitrary symbols are currently broken on GPU")
+
+    size = (4, 4)
+
+    dh = create_data_handling(size, default_target=target, default_ghost_layers=0)
+
+    src_field = dh.add_array("src", 1)
+    dst_field = dh.add_array("dst", 1)
+
+    dh.fill(src_field.name, 1.0, ghost_layers=True)
+    dh.fill(dst_field.name, 0.0, ghost_layers=True)
+
+    a, b = sp.symbols("a b")
+    update_rule = Assignment(
+        dst_field[0, 0],
+        (
+            a * src_field[0, 1]
+            + a * src_field[0, -1]
+            + b * src_field[1, 0]
+            + b * src_field[-1, 0]
+        )
+        / 4,
+    )
 
     x_end = TypedSymbol("x_end", "int")
     s = make_slice[1:x_end, 1]
     x_end_value = size[1] - 1
-    kernel = create_kernel(sympy_cse_on_assignment_list([update_rule]), iteration_slice=s).compile()
+    kernel = create_kernel(
+        sympy_cse_on_assignment_list([update_rule]), iteration_slice=s, target=target
+    ).compile()
+
+    if target == Target.GPU:
+        dh.all_to_gpu()
+
+    dh.run_kernel(kernel, a=1.0, b=1.0, x_end=x_end_value)
 
-    kernel(src=src_arr, dst=dst_arr, a=1.0, b=1.0, x_end=x_end_value)
+    if target == Target.GPU:
+        dh.all_to_cpu()
 
     expected_result = np.zeros(size)
     expected_result[1:x_end_value, 1] = 1
-    np.testing.assert_almost_equal(expected_result, dst_arr)
+    np.testing.assert_almost_equal(dh.gather_array(dst_field.name), expected_result)

tests/test_vectorization.py

@@ -143,10 +143,10 @@ def test_aligned_and_nt_stores(openmp, instruction_set=instruction_set):
     # Without the base pointer spec, the inner store is not aligned
     config = pystencils.config.CreateKernelConfig(target=dh.default_target, cpu_vectorize_info=opt, cpu_openmp=openmp)
     ast = ps.create_kernel(update_rule, config=config)
-    if instruction_set in ['sse'] or instruction_set.startswith('avx'):
+    if instruction_set in ['sse'] or instruction_set.startswith('avx') or instruction_set.startswith('sve'):
         assert 'stream' in ast.instruction_set
         assert 'streamFence' in ast.instruction_set
-    if instruction_set in ['neon', 'vsx'] or instruction_set.startswith('sve'):
+    if instruction_set in ['neon', 'vsx', 'rvv']:
         assert 'cachelineZero' in ast.instruction_set
     if instruction_set in ['vsx']:
         assert 'storeAAndFlushCacheline' in ast.instruction_set
@@ -331,7 +331,7 @@ def test_logical_operators(instruction_set=instruction_set):
 
 
 def test_hardware_query():
-    assert {'sse', 'neon', 'sve', 'vsx', 'rvv'}.intersection(supported_instruction_sets)
+    assert {'sse', 'neon', 'sve', 'sve2', 'sme', 'vsx', 'rvv'}.intersection(supported_instruction_sets)
 
 
 def test_vectorised_pow(instruction_set=instruction_set):

tests/test_vectorization_specific.py

@@ -8,8 +8,10 @@ import sympy as sp
 import pystencils as ps
 from pystencils.backends.simd_instruction_sets import (get_cacheline_size, get_supported_instruction_sets,
                                                        get_vector_instruction_set)
-from . import test_vectorization
 from pystencils.enums import Target
+from pystencils.typing import CFunction
+from . import test_vectorization
+
 
 supported_instruction_sets = get_supported_instruction_sets() if get_supported_instruction_sets() else []
 
@@ -39,7 +41,7 @@ def test_vectorisation_varying_arch(instruction_set):
 
 @pytest.mark.parametrize('dtype', ('float32', 'float64'))
 @pytest.mark.parametrize('instruction_set', supported_instruction_sets)
-def test_vectorized_abs(instruction_set, dtype):
+def test_vectorized_abs_field(instruction_set, dtype):
     """Some instructions sets have abs, some don't.
        Furthermore, the special treatment of unary minus makes this data type-sensitive too.
     """
@@ -58,24 +60,47 @@ def test_vectorized_abs(instruction_set, dtype):
     np.testing.assert_equal(np.sum(dst[1:-1, 1:-1]), 2 ** 2 * 2 ** 3)
 
 
+@pytest.mark.parametrize('instruction_set', supported_instruction_sets)
+def test_vectorized_abs_scalar(instruction_set):
+    """Some instructions sets have abs, some don't.
+       Furthermore, the special treatment of unary minus makes this data type-sensitive too.
+    """
+    arr = np.zeros((2 ** 2 + 2, 2 ** 3 + 2), dtype="float64")
+
+    f = ps.fields(f=arr)
+    update_rule = [ps.Assignment(f.center(), sp.Abs(sp.Symbol("a")))]
+
+    config = pystencils.config.CreateKernelConfig(cpu_vectorize_info={'instruction_set': instruction_set})
+    ast = ps.create_kernel(update_rule, config=config)
+
+    func = ast.compile()
+    func(f=arr, a=-1)
+    np.testing.assert_equal(np.sum(arr[1:-1, 1:-1]), 2 ** 2 * 2 ** 3)
+
+
 @pytest.mark.parametrize('dtype', ('float32', 'float64'))
 @pytest.mark.parametrize('instruction_set', supported_instruction_sets)
-def test_strided(instruction_set, dtype):
+@pytest.mark.parametrize('nontemporal', [False, True])
+def test_strided(instruction_set, dtype, nontemporal):
     f, g = ps.fields(f"f, g : {dtype}[2D]")
     update_rule = [ps.Assignment(g[0, 0], f[0, 0] + f[-1, 0] + f[1, 0] + f[0, 1] + f[0, -1] + 42.0)]
+    config = pystencils.config.CreateKernelConfig(cpu_vectorize_info={'instruction_set': instruction_set,
+                                                                      'nontemporal': nontemporal},
+                                                  default_number_float=dtype)
     if 'storeS' not in get_vector_instruction_set(dtype, instruction_set) \
             and instruction_set not in ['avx512', 'avx512vl', 'rvv'] and not instruction_set.startswith('sve'):
         with pytest.warns(UserWarning) as warn:
-            config = pystencils.config.CreateKernelConfig(cpu_vectorize_info={'instruction_set': instruction_set},
-                                                          default_number_float=dtype)
             ast = ps.create_kernel(update_rule, config=config)
             assert 'Could not vectorize loop' in warn[0].message.args[0]
     else:
         with pytest.warns(None) as warn:
-            config = pystencils.config.CreateKernelConfig(cpu_vectorize_info={'instruction_set': instruction_set},
-                                                          default_number_float=dtype)
             ast = ps.create_kernel(update_rule, config=config)
             assert len(warn) == 0
+        instruction = 'streamS' if nontemporal and 'streamS' in ast.instruction_set else 'storeS'
+        assert ast.instruction_set[instruction].split('{')[0] in ps.get_code_str(ast)
+    instruction = 'cachelineZero'
+    if instruction in ast.instruction_set:
+        assert ast.instruction_set[instruction] not in ps.get_code_str(ast)
 
     # ps.show_code(ast)
     func = ast.compile()
@@ -226,7 +251,7 @@ def test_issue62(dtype, instruction_set, padding):
     dy = sp.Symbol("dy")
     src, dst, rhs = ps.fields(f"src, src_tmp, rhs: {dtype}[2D]", layout='fzyx')
 
-    up = ps.Assignment(src[0, 0], ((dy ** 2 * (src[1, 0] + src[-1, 0]))
+    up = ps.Assignment(dst[0, 0], ((dy ** 2 * (src[1, 0] + src[-1, 0]))
                                    + (dx ** 2 * (src[0, 1] + src[0, -1]))
                                    - (rhs[0, 0] * dx ** 2 * dy ** 2)) / (2 * (dx ** 2 + dy ** 2)))
 
@@ -269,6 +294,22 @@ def test_div_and_unevaluated_expr(dtype, instruction_set):
     assert 'pow' not in code
 
 
+@pytest.mark.parametrize('dtype', ('float32', 'float64'))
+@pytest.mark.parametrize('instruction_set', ('sve', 'sve2', 'sme', 'rvv'))
+def test_check_ast_parameters_sizeless(dtype, instruction_set):
+    f, g = ps.fields(f"f, g: {dtype}[3D]", layout='fzyx')
+
+    update_rule = [ps.Assignment(g.center(), 2 * f.center())]
+
+    config = pystencils.config.CreateKernelConfig(data_type=dtype,
+                                                  cpu_vectorize_info={'instruction_set': instruction_set})
+    ast = ps.create_kernel(update_rule, config=config)
+    ast_symbols = [p.symbol for p in ast.get_parameters()]
+    assert ast.instruction_set['width'] not in ast_symbols
+    assert ast.instruction_set['intwidth'] not in ast_symbols
+
+
+
 # TODO this test case needs a complete rework of the vectoriser. The reason is that the vectoriser does not
 # TODO vectorise symbols at the moment because they could be strides or field sizes, thus involved in pointer arithmetic
 # TODO This means that the vectoriser only works if fields are involved on the rhs.

versioneer.py

-
-# Version: 0.19
-
-"""The Versioneer - like a rocketeer, but for versions.
-
-The Versioneer
-==============
-
-* like a rocketeer, but for versions!
-* https://github.com/python-versioneer/python-versioneer
-* Brian Warner
-* License: Public Domain
-* Compatible with: Python 3.6, 3.7, 3.8, 3.9 and pypy3
-* [![Latest Version][pypi-image]][pypi-url]
-* [![Build Status][travis-image]][travis-url]
-
-This is a tool for managing a recorded version number in distutils-based
-python projects. The goal is to remove the tedious and error-prone "update
-the embedded version string" step from your release process. Making a new
-release should be as easy as recording a new tag in your version-control
-system, and maybe making new tarballs.
-
-
-## Quick Install
-
-* `pip install versioneer` to somewhere in your $PATH
-* add a `[versioneer]` section to your setup.cfg (see [Install](INSTALL.md))
-* run `versioneer install` in your source tree, commit the results
-* Verify version information with `python setup.py version`
-
-## Version Identifiers
-
-Source trees come from a variety of places:
-
-* a version-control system checkout (mostly used by developers)
-* a nightly tarball, produced by build automation
-* a snapshot tarball, produced by a web-based VCS browser, like github's
-  "tarball from tag" feature
-* a release tarball, produced by "setup.py sdist", distributed through PyPI
-
-Within each source tree, the version identifier (either a string or a number,
-this tool is format-agnostic) can come from a variety of places:
-
-* ask the VCS tool itself, e.g. "git describe" (for checkouts), which knows
-  about recent "tags" and an absolute revision-id
-* the name of the directory into which the tarball was unpacked
-* an expanded VCS keyword ($Id$, etc)
-* a `_version.py` created by some earlier build step
-
-For released software, the version identifier is closely related to a VCS
-tag. Some projects use tag names that include more than just the version
-string (e.g. "myproject-1.2" instead of just "1.2"), in which case the tool
-needs to strip the tag prefix to extract the version identifier. For
-unreleased software (between tags), the version identifier should provide
-enough information to help developers recreate the same tree, while also
-giving them an idea of roughly how old the tree is (after version 1.2, before
-version 1.3). Many VCS systems can report a description that captures this,
-for example `git describe --tags --dirty --always` reports things like
-"0.7-1-g574ab98-dirty" to indicate that the checkout is one revision past the
-0.7 tag, has a unique revision id of "574ab98", and is "dirty" (it has
-uncommitted changes).
-
-The version identifier is used for multiple purposes:
-
-* to allow the module to self-identify its version: `myproject.__version__`
-* to choose a name and prefix for a 'setup.py sdist' tarball
-
-## Theory of Operation
-
-Versioneer works by adding a special `_version.py` file into your source
-tree, where your `__init__.py` can import it. This `_version.py` knows how to
-dynamically ask the VCS tool for version information at import time.
-
-`_version.py` also contains `$Revision$` markers, and the installation
-process marks `_version.py` to have this marker rewritten with a tag name
-during the `git archive` command. As a result, generated tarballs will
-contain enough information to get the proper version.
-
-To allow `setup.py` to compute a version too, a `versioneer.py` is added to
-the top level of your source tree, next to `setup.py` and the `setup.cfg`
-that configures it. This overrides several distutils/setuptools commands to
-compute the version when invoked, and changes `setup.py build` and `setup.py
-sdist` to replace `_version.py` with a small static file that contains just
-the generated version data.
-
-## Installation
-
-See [INSTALL.md](./INSTALL.md) for detailed installation instructions.
-
-## Version-String Flavors
-
-Code which uses Versioneer can learn about its version string at runtime by
-importing `_version` from your main `__init__.py` file and running the
-`get_versions()` function. From the "outside" (e.g. in `setup.py`), you can
-import the top-level `versioneer.py` and run `get_versions()`.
-
-Both functions return a dictionary with different flavors of version
-information:
-
-* `['version']`: A condensed version string, rendered using the selected
-  style. This is the most commonly used value for the project's version
-  string. The default "pep440" style yields strings like `0.11`,
-  `0.11+2.g1076c97`, or `0.11+2.g1076c97.dirty`. See the "Styles" section
-  below for alternative styles.
-
-* `['full-revisionid']`: detailed revision identifier. For Git, this is the
-  full SHA1 commit id, e.g. "1076c978a8d3cfc70f408fe5974aa6c092c949ac".
-
-* `['date']`: Date and time of the latest `HEAD` commit. For Git, it is the
-  commit date in ISO 8601 format. This will be None if the date is not
-  available.
-
-* `['dirty']`: a boolean, True if the tree has uncommitted changes. Note that
-  this is only accurate if run in a VCS checkout, otherwise it is likely to
-  be False or None
-
-* `['error']`: if the version string could not be computed, this will be set
-  to a string describing the problem, otherwise it will be None. It may be
-  useful to throw an exception in setup.py if this is set, to avoid e.g.
-  creating tarballs with a version string of "unknown".
-
-Some variants are more useful than others. Including `full-revisionid` in a
-bug report should allow developers to reconstruct the exact code being tested
-(or indicate the presence of local changes that should be shared with the
-developers). `version` is suitable for display in an "about" box or a CLI
-`--version` output: it can be easily compared against release notes and lists
-of bugs fixed in various releases.
-
-The installer adds the following text to your `__init__.py` to place a basic
-version in `YOURPROJECT.__version__`:
-
-    from ._version import get_versions
-    __version__ = get_versions()['version']
-    del get_versions
-
-## Styles
-
-The setup.cfg `style=` configuration controls how the VCS information is
-rendered into a version string.
-
-The default style, "pep440", produces a PEP440-compliant string, equal to the
-un-prefixed tag name for actual releases, and containing an additional "local
-version" section with more detail for in-between builds. For Git, this is
-TAG[+DISTANCE.gHEX[.dirty]] , using information from `git describe --tags
---dirty --always`. For example "0.11+2.g1076c97.dirty" indicates that the
-tree is like the "1076c97" commit but has uncommitted changes (".dirty"), and
-that this commit is two revisions ("+2") beyond the "0.11" tag. For released
-software (exactly equal to a known tag), the identifier will only contain the
-stripped tag, e.g. "0.11".
-
-Other styles are available. See [details.md](details.md) in the Versioneer
-source tree for descriptions.
-
-## Debugging
-
-Versioneer tries to avoid fatal errors: if something goes wrong, it will tend
-to return a version of "0+unknown". To investigate the problem, run `setup.py
-version`, which will run the version-lookup code in a verbose mode, and will
-display the full contents of `get_versions()` (including the `error` string,
-which may help identify what went wrong).
-
-## Known Limitations
-
-Some situations are known to cause problems for Versioneer. This details the
-most significant ones. More can be found on Github
-[issues page](https://github.com/python-versioneer/python-versioneer/issues).
-
-### Subprojects
-
-Versioneer has limited support for source trees in which `setup.py` is not in
-the root directory (e.g. `setup.py` and `.git/` are *not* siblings). The are
-two common reasons why `setup.py` might not be in the root:
-
-* Source trees which contain multiple subprojects, such as
-  [Buildbot](https://github.com/buildbot/buildbot), which contains both
-  "master" and "slave" subprojects, each with their own `setup.py`,
-  `setup.cfg`, and `tox.ini`. Projects like these produce multiple PyPI
-  distributions (and upload multiple independently-installable tarballs).
-* Source trees whose main purpose is to contain a C library, but which also
-  provide bindings to Python (and perhaps other languages) in subdirectories.
-
-Versioneer will look for `.git` in parent directories, and most operations
-should get the right version string. However `pip` and `setuptools` have bugs
-and implementation details which frequently cause `pip install .` from a
-subproject directory to fail to find a correct version string (so it usually
-defaults to `0+unknown`).
-
-`pip install --editable .` should work correctly. `setup.py install` might
-work too.
-
-Pip-8.1.1 is known to have this problem, but hopefully it will get fixed in
-some later version.
-
-[Bug #38](https://github.com/python-versioneer/python-versioneer/issues/38) is tracking
-this issue. The discussion in
-[PR #61](https://github.com/python-versioneer/python-versioneer/pull/61) describes the
-issue from the Versioneer side in more detail.
-[pip PR#3176](https://github.com/pypa/pip/pull/3176) and
-[pip PR#3615](https://github.com/pypa/pip/pull/3615) contain work to improve
-pip to let Versioneer work correctly.
-
-Versioneer-0.16 and earlier only looked for a `.git` directory next to the
-`setup.cfg`, so subprojects were completely unsupported with those releases.
-
-### Editable installs with setuptools <= 18.5
-
-`setup.py develop` and `pip install --editable .` allow you to install a
-project into a virtualenv once, then continue editing the source code (and
-test) without re-installing after every change.
-
-"Entry-point scripts" (`setup(entry_points={"console_scripts": ..})`) are a
-convenient way to specify executable scripts that should be installed along
-with the python package.
-
-These both work as expected when using modern setuptools. When using
-setuptools-18.5 or earlier, however, certain operations will cause
-`pkg_resources.DistributionNotFound` errors when running the entrypoint
-script, which must be resolved by re-installing the package. This happens
-when the install happens with one version, then the egg_info data is
-regenerated while a different version is checked out. Many setup.py commands
-cause egg_info to be rebuilt (including `sdist`, `wheel`, and installing into
-a different virtualenv), so this can be surprising.
-
-[Bug #83](https://github.com/python-versioneer/python-versioneer/issues/83) describes
-this one, but upgrading to a newer version of setuptools should probably
-resolve it.
-
-
-## Updating Versioneer
-
-To upgrade your project to a new release of Versioneer, do the following:
-
-* install the new Versioneer (`pip install -U versioneer` or equivalent)
-* edit `setup.cfg`, if necessary, to include any new configuration settings
-  indicated by the release notes. See [UPGRADING](./UPGRADING.md) for details.
-* re-run `versioneer install` in your source tree, to replace
-  `SRC/_version.py`
-* commit any changed files
-
-## Future Directions
-
-This tool is designed to make it easily extended to other version-control
-systems: all VCS-specific components are in separate directories like
-src/git/ . The top-level `versioneer.py` script is assembled from these
-components by running make-versioneer.py . In the future, make-versioneer.py
-will take a VCS name as an argument, and will construct a version of
-`versioneer.py` that is specific to the given VCS. It might also take the
-configuration arguments that are currently provided manually during
-installation by editing setup.py . Alternatively, it might go the other
-direction and include code from all supported VCS systems, reducing the
-number of intermediate scripts.
-
-## Similar projects
-
-* [setuptools_scm](https://github.com/pypa/setuptools_scm/) - a non-vendored build-time
-  dependency
-* [minver](https://github.com/jbweston/miniver) - a lightweight reimplementation of
-  versioneer
-
-## License
-
-To make Versioneer easier to embed, all its code is dedicated to the public
-domain. The `_version.py` that it creates is also in the public domain.
-Specifically, both are released under the Creative Commons "Public Domain
-Dedication" license (CC0-1.0), as described in
-https://creativecommons.org/publicdomain/zero/1.0/ .
-
-[pypi-image]: https://img.shields.io/pypi/v/versioneer.svg
-[pypi-url]: https://pypi.python.org/pypi/versioneer/
-[travis-image]:
-https://img.shields.io/travis/com/python-versioneer/python-versioneer.svg
-[travis-url]: https://travis-ci.com/github/python-versioneer/python-versioneer
-
-"""
-
-import configparser
-import errno
-import json
-import os
-import re
-import subprocess
-import sys
-
-
-class VersioneerConfig:
-    """Container for Versioneer configuration parameters."""
-
-
-def get_root():
-    """Get the project root directory.
-
-    We require that all commands are run from the project root, i.e. the
-    directory that contains setup.py, setup.cfg, and versioneer.py .
-    """
-    root = os.path.realpath(os.path.abspath(os.getcwd()))
-    setup_py = os.path.join(root, "setup.py")
-    versioneer_py = os.path.join(root, "versioneer.py")
-    if not (os.path.exists(setup_py) or os.path.exists(versioneer_py)):
-        # allow 'python path/to/setup.py COMMAND'
-        root = os.path.dirname(os.path.realpath(os.path.abspath(sys.argv[0])))
-        setup_py = os.path.join(root, "setup.py")
-        versioneer_py = os.path.join(root, "versioneer.py")
-    if not (os.path.exists(setup_py) or os.path.exists(versioneer_py)):
-        err = ("Versioneer was unable to run the project root directory. "
-               "Versioneer requires setup.py to be executed from "
-               "its immediate directory (like 'python setup.py COMMAND'), "
-               "or in a way that lets it use sys.argv[0] to find the root "
-               "(like 'python path/to/setup.py COMMAND').")
-        raise VersioneerBadRootError(err)
-    try:
-        # Certain runtime workflows (setup.py install/develop in a setuptools
-        # tree) execute all dependencies in a single python process, so
-        # "versioneer" may be imported multiple times, and python's shared
-        # module-import table will cache the first one. So we can't use
-        # os.path.dirname(__file__), as that will find whichever
-        # versioneer.py was first imported, even in later projects.
-        me = os.path.realpath(os.path.abspath(__file__))
-        me_dir = os.path.normcase(os.path.splitext(me)[0])
-        vsr_dir = os.path.normcase(os.path.splitext(versioneer_py)[0])
-        if me_dir != vsr_dir:
-            print("Warning: build in %s is using versioneer.py from %s"
-                  % (os.path.dirname(me), versioneer_py))
-    except NameError:
-        pass
-    return root
-
-
-def get_config_from_root(root):
-    """Read the project setup.cfg file to determine Versioneer config."""
-    # This might raise EnvironmentError (if setup.cfg is missing), or
-    # configparser.NoSectionError (if it lacks a [versioneer] section), or
-    # configparser.NoOptionError (if it lacks "VCS="). See the docstring at
-    # the top of versioneer.py for instructions on writing your setup.cfg .
-    setup_cfg = os.path.join(root, "setup.cfg")
-    parser = configparser.ConfigParser()
-    with open(setup_cfg, "r") as f:
-        parser.read_file(f)
-    VCS = parser.get("versioneer", "VCS")  # mandatory
-
-    def get(parser, name):
-        if parser.has_option("versioneer", name):
-            return parser.get("versioneer", name)
-        return None
-    cfg = VersioneerConfig()
-    cfg.VCS = VCS
-    cfg.style = get(parser, "style") or ""
-    cfg.versionfile_source = get(parser, "versionfile_source")
-    cfg.versionfile_build = get(parser, "versionfile_build")
-    cfg.tag_prefix = get(parser, "tag_prefix")
-    if cfg.tag_prefix in ("''", '""'):
-        cfg.tag_prefix = ""
-    cfg.parentdir_prefix = get(parser, "parentdir_prefix")
-    cfg.verbose = get(parser, "verbose")
-    return cfg
-
-
-class NotThisMethod(Exception):
-    """Exception raised if a method is not valid for the current scenario."""
-
-
-# these dictionaries contain VCS-specific tools
-LONG_VERSION_PY = {}
-HANDLERS = {}
-
-
-def register_vcs_handler(vcs, method):  # decorator
-    """Create decorator to mark a method as the handler of a VCS."""
-    def decorate(f):
-        """Store f in HANDLERS[vcs][method]."""
-        if vcs not in HANDLERS:
-            HANDLERS[vcs] = {}
-        HANDLERS[vcs][method] = f
-        return f
-    return decorate
-
-
-def run_command(commands, args, cwd=None, verbose=False, hide_stderr=False,
-                env=None):
-    """Call the given command(s)."""
-    assert isinstance(commands, list)
-    p = None
-    for c in commands:
-        try:
-            dispcmd = str([c] + args)
-            # remember shell=False, so use git.cmd on windows, not just git
-            p = subprocess.Popen([c] + args, cwd=cwd, env=env,
-                                 stdout=subprocess.PIPE,
-                                 stderr=(subprocess.PIPE if hide_stderr
-                                         else None))
-            break
-        except EnvironmentError:
-            e = sys.exc_info()[1]
-            if e.errno == errno.ENOENT:
-                continue
-            if verbose:
-                print("unable to run %s" % dispcmd)
-                print(e)
-            return None, None
-    else:
-        if verbose:
-            print("unable to find command, tried %s" % (commands,))
-        return None, None
-    stdout = p.communicate()[0].strip().decode()
-    if p.returncode != 0:
-        if verbose:
-            print("unable to run %s (error)" % dispcmd)
-            print("stdout was %s" % stdout)
-        return None, p.returncode
-    return stdout, p.returncode
-
-
-LONG_VERSION_PY['git'] = r'''
-# This file helps to compute a version number in source trees obtained from
-# git-archive tarball (such as those provided by githubs download-from-tag
-# feature). Distribution tarballs (built by setup.py sdist) and build
-# directories (produced by setup.py build) will contain a much shorter file
-# that just contains the computed version number.
-
-# This file is released into the public domain. Generated by
-# versioneer-0.19 (https://github.com/python-versioneer/python-versioneer)
-
-"""Git implementation of _version.py."""
-
-import errno
-import os
-import re
-import subprocess
-import sys
-
-
-def get_keywords():
-    """Get the keywords needed to look up the version information."""
-    # these strings will be replaced by git during git-archive.
-    # setup.py/versioneer.py will grep for the variable names, so they must
-    # each be defined on a line of their own. _version.py will just call
-    # get_keywords().
-    git_refnames = "%(DOLLAR)sFormat:%%d%(DOLLAR)s"
-    git_full = "%(DOLLAR)sFormat:%%H%(DOLLAR)s"
-    git_date = "%(DOLLAR)sFormat:%%ci%(DOLLAR)s"
-    keywords = {"refnames": git_refnames, "full": git_full, "date": git_date}
-    return keywords
-
-
-class VersioneerConfig:
-    """Container for Versioneer configuration parameters."""
-
-
-def get_config():
-    """Create, populate and return the VersioneerConfig() object."""
-    # these strings are filled in when 'setup.py versioneer' creates
-    # _version.py
-    cfg = VersioneerConfig()
-    cfg.VCS = "git"
-    cfg.style = "%(STYLE)s"
-    cfg.tag_prefix = "%(TAG_PREFIX)s"
-    cfg.parentdir_prefix = "%(PARENTDIR_PREFIX)s"
-    cfg.versionfile_source = "%(VERSIONFILE_SOURCE)s"
-    cfg.verbose = False
-    return cfg
-
-
-class NotThisMethod(Exception):
-    """Exception raised if a method is not valid for the current scenario."""
-
-
-LONG_VERSION_PY = {}
-HANDLERS = {}
-
-
-def register_vcs_handler(vcs, method):  # decorator
-    """Create decorator to mark a method as the handler of a VCS."""
-    def decorate(f):
-        """Store f in HANDLERS[vcs][method]."""
-        if vcs not in HANDLERS:
-            HANDLERS[vcs] = {}
-        HANDLERS[vcs][method] = f
-        return f
-    return decorate
-
-
-def run_command(commands, args, cwd=None, verbose=False, hide_stderr=False,
-                env=None):
-    """Call the given command(s)."""
-    assert isinstance(commands, list)
-    p = None
-    for c in commands:
-        try:
-            dispcmd = str([c] + args)
-            # remember shell=False, so use git.cmd on windows, not just git
-            p = subprocess.Popen([c] + args, cwd=cwd, env=env,
-                                 stdout=subprocess.PIPE,
-                                 stderr=(subprocess.PIPE if hide_stderr
-                                         else None))
-            break
-        except EnvironmentError:
-            e = sys.exc_info()[1]
-            if e.errno == errno.ENOENT:
-                continue
-            if verbose:
-                print("unable to run %%s" %% dispcmd)
-                print(e)
-            return None, None
-    else:
-        if verbose:
-            print("unable to find command, tried %%s" %% (commands,))
-        return None, None
-    stdout = p.communicate()[0].strip().decode()
-    if p.returncode != 0:
-        if verbose:
-            print("unable to run %%s (error)" %% dispcmd)
-            print("stdout was %%s" %% stdout)
-        return None, p.returncode
-    return stdout, p.returncode
-
-
-def versions_from_parentdir(parentdir_prefix, root, verbose):
-    """Try to determine the version from the parent directory name.
-
-    Source tarballs conventionally unpack into a directory that includes both
-    the project name and a version string. We will also support searching up
-    two directory levels for an appropriately named parent directory
-    """
-    rootdirs = []
-
-    for i in range(3):
-        dirname = os.path.basename(root)
-        if dirname.startswith(parentdir_prefix):
-            return {"version": dirname[len(parentdir_prefix):],
-                    "full-revisionid": None,
-                    "dirty": False, "error": None, "date": None}
-        else:
-            rootdirs.append(root)
-            root = os.path.dirname(root)  # up a level
-
-    if verbose:
-        print("Tried directories %%s but none started with prefix %%s" %%
-              (str(rootdirs), parentdir_prefix))
-    raise NotThisMethod("rootdir doesn't start with parentdir_prefix")
-
-
-@register_vcs_handler("git", "get_keywords")
-def git_get_keywords(versionfile_abs):
-    """Extract version information from the given file."""
-    # the code embedded in _version.py can just fetch the value of these
-    # keywords. When used from setup.py, we don't want to import _version.py,
-    # so we do it with a regexp instead. This function is not used from
-    # _version.py.
-    keywords = {}
-    try:
-        f = open(versionfile_abs, "r")
-        for line in f.readlines():
-            if line.strip().startswith("git_refnames ="):
-                mo = re.search(r'=\s*"(.*)"', line)
-                if mo:
-                    keywords["refnames"] = mo.group(1)
-            if line.strip().startswith("git_full ="):
-                mo = re.search(r'=\s*"(.*)"', line)
-                if mo:
-                    keywords["full"] = mo.group(1)
-            if line.strip().startswith("git_date ="):
-                mo = re.search(r'=\s*"(.*)"', line)
-                if mo:
-                    keywords["date"] = mo.group(1)
-        f.close()
-    except EnvironmentError:
-        pass
-    return keywords
-
-
-@register_vcs_handler("git", "keywords")
-def git_versions_from_keywords(keywords, tag_prefix, verbose):
-    """Get version information from git keywords."""
-    if not keywords:
-        raise NotThisMethod("no keywords at all, weird")
-    date = keywords.get("date")
-    if date is not None:
-        # Use only the last line.  Previous lines may contain GPG signature
-        # information.
-        date = date.splitlines()[-1]
-
-        # git-2.2.0 added "%%cI", which expands to an ISO-8601 -compliant
-        # datestamp. However we prefer "%%ci" (which expands to an "ISO-8601
-        # -like" string, which we must then edit to make compliant), because
-        # it's been around since git-1.5.3, and it's too difficult to
-        # discover which version we're using, or to work around using an
-        # older one.
-        date = date.strip().replace(" ", "T", 1).replace(" ", "", 1)
-    refnames = keywords["refnames"].strip()
-    if refnames.startswith("$Format"):
-        if verbose:
-            print("keywords are unexpanded, not using")
-        raise NotThisMethod("unexpanded keywords, not a git-archive tarball")
-    refs = set([r.strip() for r in refnames.strip("()").split(",")])
-    # starting in git-1.8.3, tags are listed as "tag: foo-1.0" instead of
-    # just "foo-1.0". If we see a "tag: " prefix, prefer those.
-    TAG = "tag: "
-    tags = set([r[len(TAG):] for r in refs if r.startswith(TAG)])
-    if not tags:
-        # Either we're using git < 1.8.3, or there really are no tags. We use
-        # a heuristic: assume all version tags have a digit. The old git %%d
-        # expansion behaves like git log --decorate=short and strips out the
-        # refs/heads/ and refs/tags/ prefixes that would let us distinguish
-        # between branches and tags. By ignoring refnames without digits, we
-        # filter out many common branch names like "release" and
-        # "stabilization", as well as "HEAD" and "master".
-        tags = set([r for r in refs if re.search(r'\d', r)])
-        if verbose:
-            print("discarding '%%s', no digits" %% ",".join(refs - tags))
-    if verbose:
-        print("likely tags: %%s" %% ",".join(sorted(tags)))
-    for ref in sorted(tags):
-        # sorting will prefer e.g. "2.0" over "2.0rc1"
-        if ref.startswith(tag_prefix):
-            r = ref[len(tag_prefix):]
-            if verbose:
-                print("picking %%s" %% r)
-            return {"version": r,
-                    "full-revisionid": keywords["full"].strip(),
-                    "dirty": False, "error": None,
-                    "date": date}
-    # no suitable tags, so version is "0+unknown", but full hex is still there
-    if verbose:
-        print("no suitable tags, using unknown + full revision id")
-    return {"version": "0+unknown",
-            "full-revisionid": keywords["full"].strip(),
-            "dirty": False, "error": "no suitable tags", "date": None}
-
-
-@register_vcs_handler("git", "pieces_from_vcs")
-def git_pieces_from_vcs(tag_prefix, root, verbose, run_command=run_command):
-    """Get version from 'git describe' in the root of the source tree.
-
-    This only gets called if the git-archive 'subst' keywords were *not*
-    expanded, and _version.py hasn't already been rewritten with a short
-    version string, meaning we're inside a checked out source tree.
-    """
-    GITS = ["git"]
-    if sys.platform == "win32":
-        GITS = ["git.cmd", "git.exe"]
-
-    out, rc = run_command(GITS, ["rev-parse", "--git-dir"], cwd=root,
-                          hide_stderr=True)
-    if rc != 0:
-        if verbose:
-            print("Directory %%s not under git control" %% root)
-        raise NotThisMethod("'git rev-parse --git-dir' returned error")
-
-    # if there is a tag matching tag_prefix, this yields TAG-NUM-gHEX[-dirty]
-    # if there isn't one, this yields HEX[-dirty] (no NUM)
-    describe_out, rc = run_command(GITS, ["describe", "--tags", "--dirty",
-                                          "--always", "--long",
-                                          "--match", "%%s*" %% tag_prefix],
-                                   cwd=root)
-    # --long was added in git-1.5.5
-    if describe_out is None:
-        raise NotThisMethod("'git describe' failed")
-    describe_out = describe_out.strip()
-    full_out, rc = run_command(GITS, ["rev-parse", "HEAD"], cwd=root)
-    if full_out is None:
-        raise NotThisMethod("'git rev-parse' failed")
-    full_out = full_out.strip()
-
-    pieces = {}
-    pieces["long"] = full_out
-    pieces["short"] = full_out[:7]  # maybe improved later
-    pieces["error"] = None
-
-    # parse describe_out. It will be like TAG-NUM-gHEX[-dirty] or HEX[-dirty]
-    # TAG might have hyphens.
-    git_describe = describe_out
-
-    # look for -dirty suffix
-    dirty = git_describe.endswith("-dirty")
-    pieces["dirty"] = dirty
-    if dirty:
-        git_describe = git_describe[:git_describe.rindex("-dirty")]
-
-    # now we have TAG-NUM-gHEX or HEX
-
-    if "-" in git_describe:
-        # TAG-NUM-gHEX
-        mo = re.search(r'^(.+)-(\d+)-g([0-9a-f]+)$', git_describe)
-        if not mo:
-            # unparseable. Maybe git-describe is misbehaving?
-            pieces["error"] = ("unable to parse git-describe output: '%%s'"
-                               %% describe_out)
-            return pieces
-
-        # tag
-        full_tag = mo.group(1)
-        if not full_tag.startswith(tag_prefix):
-            if verbose:
-                fmt = "tag '%%s' doesn't start with prefix '%%s'"
-                print(fmt %% (full_tag, tag_prefix))
-            pieces["error"] = ("tag '%%s' doesn't start with prefix '%%s'"
-                               %% (full_tag, tag_prefix))
-            return pieces
-        pieces["closest-tag"] = full_tag[len(tag_prefix):]
-
-        # distance: number of commits since tag
-        pieces["distance"] = int(mo.group(2))
-
-        # commit: short hex revision ID
-        pieces["short"] = mo.group(3)
-
-    else:
-        # HEX: no tags
-        pieces["closest-tag"] = None
-        count_out, rc = run_command(GITS, ["rev-list", "HEAD", "--count"],
-                                    cwd=root)
-        pieces["distance"] = int(count_out)  # total number of commits
-
-    # commit date: see ISO-8601 comment in git_versions_from_keywords()
-    date = run_command(GITS, ["show", "-s", "--format=%%ci", "HEAD"],
-                       cwd=root)[0].strip()
-    # Use only the last line.  Previous lines may contain GPG signature
-    # information.
-    date = date.splitlines()[-1]
-    pieces["date"] = date.strip().replace(" ", "T", 1).replace(" ", "", 1)
-
-    return pieces
-
-
-def plus_or_dot(pieces):
-    """Return a + if we don't already have one, else return a ."""
-    if "+" in pieces.get("closest-tag", ""):
-        return "."
-    return "+"
-
-
-def render_pep440(pieces):
-    """Build up version string, with post-release "local version identifier".
-
-    Our goal: TAG[+DISTANCE.gHEX[.dirty]] . Note that if you
-    get a tagged build and then dirty it, you'll get TAG+0.gHEX.dirty
-
-    Exceptions:
-    1: no tags. git_describe was just HEX. 0+untagged.DISTANCE.gHEX[.dirty]
-    """
-    if pieces["closest-tag"]:
-        rendered = pieces["closest-tag"]
-        if pieces["distance"] or pieces["dirty"]:
-            rendered += plus_or_dot(pieces)
-            rendered += "%%d.g%%s" %% (pieces["distance"], pieces["short"])
-            if pieces["dirty"]:
-                rendered += ".dirty"
-    else:
-        # exception #1
-        rendered = "0+untagged.%%d.g%%s" %% (pieces["distance"],
-                                          pieces["short"])
-        if pieces["dirty"]:
-            rendered += ".dirty"
-    return rendered
-
-
-def render_pep440_pre(pieces):
-    """TAG[.post0.devDISTANCE] -- No -dirty.
-
-    Exceptions:
-    1: no tags. 0.post0.devDISTANCE
-    """
-    if pieces["closest-tag"]:
-        rendered = pieces["closest-tag"]
-        if pieces["distance"]:
-            rendered += ".post0.dev%%d" %% pieces["distance"]
-    else:
-        # exception #1
-        rendered = "0.post0.dev%%d" %% pieces["distance"]
-    return rendered
-
-
-def render_pep440_post(pieces):
-    """TAG[.postDISTANCE[.dev0]+gHEX] .
-
-    The ".dev0" means dirty. Note that .dev0 sorts backwards
-    (a dirty tree will appear "older" than the corresponding clean one),
-    but you shouldn't be releasing software with -dirty anyways.
-
-    Exceptions:
-    1: no tags. 0.postDISTANCE[.dev0]
-    """
-    if pieces["closest-tag"]:
-        rendered = pieces["closest-tag"]
-        if pieces["distance"] or pieces["dirty"]:
-            rendered += ".post%%d" %% pieces["distance"]
-            if pieces["dirty"]:
-                rendered += ".dev0"
-            rendered += plus_or_dot(pieces)
-            rendered += "g%%s" %% pieces["short"]
-    else:
-        # exception #1
-        rendered = "0.post%%d" %% pieces["distance"]
-        if pieces["dirty"]:
-            rendered += ".dev0"
-        rendered += "+g%%s" %% pieces["short"]
-    return rendered
-
-
-def render_pep440_old(pieces):
-    """TAG[.postDISTANCE[.dev0]] .
-
-    The ".dev0" means dirty.
-
-    Exceptions:
-    1: no tags. 0.postDISTANCE[.dev0]
-    """
-    if pieces["closest-tag"]:
-        rendered = pieces["closest-tag"]
-        if pieces["distance"] or pieces["dirty"]:
-            rendered += ".post%%d" %% pieces["distance"]
-            if pieces["dirty"]:
-                rendered += ".dev0"
-    else:
-        # exception #1
-        rendered = "0.post%%d" %% pieces["distance"]
-        if pieces["dirty"]:
-            rendered += ".dev0"
-    return rendered
-
-
-def render_git_describe(pieces):
-    """TAG[-DISTANCE-gHEX][-dirty].
-
-    Like 'git describe --tags --dirty --always'.
-
-    Exceptions:
-    1: no tags. HEX[-dirty]  (note: no 'g' prefix)
-    """
-    if pieces["closest-tag"]:
-        rendered = pieces["closest-tag"]
-        if pieces["distance"]:
-            rendered += "-%%d-g%%s" %% (pieces["distance"], pieces["short"])
-    else:
-        # exception #1
-        rendered = pieces["short"]
-    if pieces["dirty"]:
-        rendered += "-dirty"
-    return rendered
-
-
-def render_git_describe_long(pieces):
-    """TAG-DISTANCE-gHEX[-dirty].
-
-    Like 'git describe --tags --dirty --always -long'.
-    The distance/hash is unconditional.
-
-    Exceptions:
-    1: no tags. HEX[-dirty]  (note: no 'g' prefix)
-    """
-    if pieces["closest-tag"]:
-        rendered = pieces["closest-tag"]
-        rendered += "-%%d-g%%s" %% (pieces["distance"], pieces["short"])
-    else:
-        # exception #1
-        rendered = pieces["short"]
-    if pieces["dirty"]:
-        rendered += "-dirty"
-    return rendered
-
-
-def render(pieces, style):
-    """Render the given version pieces into the requested style."""
-    if pieces["error"]:
-        return {"version": "unknown",
-                "full-revisionid": pieces.get("long"),
-                "dirty": None,
-                "error": pieces["error"],
-                "date": None}
-
-    if not style or style == "default":
-        style = "pep440"  # the default
-
-    if style == "pep440":
-        rendered = render_pep440(pieces)
-    elif style == "pep440-pre":
-        rendered = render_pep440_pre(pieces)
-    elif style == "pep440-post":
-        rendered = render_pep440_post(pieces)
-    elif style == "pep440-old":
-        rendered = render_pep440_old(pieces)
-    elif style == "git-describe":
-        rendered = render_git_describe(pieces)
-    elif style == "git-describe-long":
-        rendered = render_git_describe_long(pieces)
-    else:
-        raise ValueError("unknown style '%%s'" %% style)
-
-    return {"version": rendered, "full-revisionid": pieces["long"],
-            "dirty": pieces["dirty"], "error": None,
-            "date": pieces.get("date")}
-
-
-def get_versions():
-    """Get version information or return default if unable to do so."""
-    # I am in _version.py, which lives at ROOT/VERSIONFILE_SOURCE. If we have
-    # __file__, we can work backwards from there to the root. Some
-    # py2exe/bbfreeze/non-CPython implementations don't do __file__, in which
-    # case we can only use expanded keywords.
-
-    cfg = get_config()
-    verbose = cfg.verbose
-
-    try:
-        return git_versions_from_keywords(get_keywords(), cfg.tag_prefix,
-                                          verbose)
-    except NotThisMethod:
-        pass
-
-    try:
-        root = os.path.realpath(__file__)
-        # versionfile_source is the relative path from the top of the source
-        # tree (where the .git directory might live) to this file. Invert
-        # this to find the root from __file__.
-        for i in cfg.versionfile_source.split('/'):
-            root = os.path.dirname(root)
-    except NameError:
-        return {"version": "0+unknown", "full-revisionid": None,
-                "dirty": None,
-                "error": "unable to find root of source tree",
-                "date": None}
-
-    try:
-        pieces = git_pieces_from_vcs(cfg.tag_prefix, root, verbose)
-        return render(pieces, cfg.style)
-    except NotThisMethod:
-        pass
-
-    try:
-        if cfg.parentdir_prefix:
-            return versions_from_parentdir(cfg.parentdir_prefix, root, verbose)
-    except NotThisMethod:
-        pass
-
-    return {"version": "0+unknown", "full-revisionid": None,
-            "dirty": None,
-            "error": "unable to compute version", "date": None}
-'''
-
-
-@register_vcs_handler("git", "get_keywords")
-def git_get_keywords(versionfile_abs):
-    """Extract version information from the given file."""
-    # the code embedded in _version.py can just fetch the value of these
-    # keywords. When used from setup.py, we don't want to import _version.py,
-    # so we do it with a regexp instead. This function is not used from
-    # _version.py.
-    keywords = {}
-    try:
-        f = open(versionfile_abs, "r")
-        for line in f.readlines():
-            if line.strip().startswith("git_refnames ="):
-                mo = re.search(r'=\s*"(.*)"', line)
-                if mo:
-                    keywords["refnames"] = mo.group(1)
-            if line.strip().startswith("git_full ="):
-                mo = re.search(r'=\s*"(.*)"', line)
-                if mo:
-                    keywords["full"] = mo.group(1)
-            if line.strip().startswith("git_date ="):
-                mo = re.search(r'=\s*"(.*)"', line)
-                if mo:
-                    keywords["date"] = mo.group(1)
-        f.close()
-    except EnvironmentError:
-        pass
-    return keywords
-
-
-@register_vcs_handler("git", "keywords")
-def git_versions_from_keywords(keywords, tag_prefix, verbose):
-    """Get version information from git keywords."""
-    if not keywords:
-        raise NotThisMethod("no keywords at all, weird")
-    date = keywords.get("date")
-    if date is not None:
-        # Use only the last line.  Previous lines may contain GPG signature
-        # information.
-        date = date.splitlines()[-1]
-
-        # git-2.2.0 added "%cI", which expands to an ISO-8601 -compliant
-        # datestamp. However we prefer "%ci" (which expands to an "ISO-8601
-        # -like" string, which we must then edit to make compliant), because
-        # it's been around since git-1.5.3, and it's too difficult to
-        # discover which version we're using, or to work around using an
-        # older one.
-        date = date.strip().replace(" ", "T", 1).replace(" ", "", 1)
-    refnames = keywords["refnames"].strip()
-    if refnames.startswith("$Format"):
-        if verbose:
-            print("keywords are unexpanded, not using")
-        raise NotThisMethod("unexpanded keywords, not a git-archive tarball")
-    refs = set([r.strip() for r in refnames.strip("()").split(",")])
-    # starting in git-1.8.3, tags are listed as "tag: foo-1.0" instead of
-    # just "foo-1.0". If we see a "tag: " prefix, prefer those.
-    TAG = "tag: "
-    tags = set([r[len(TAG):] for r in refs if r.startswith(TAG)])
-    if not tags:
-        # Either we're using git < 1.8.3, or there really are no tags. We use
-        # a heuristic: assume all version tags have a digit. The old git %d
-        # expansion behaves like git log --decorate=short and strips out the
-        # refs/heads/ and refs/tags/ prefixes that would let us distinguish
-        # between branches and tags. By ignoring refnames without digits, we
-        # filter out many common branch names like "release" and
-        # "stabilization", as well as "HEAD" and "master".
-        tags = set([r for r in refs if re.search(r'\d', r)])
-        if verbose:
-            print("discarding '%s', no digits" % ",".join(refs - tags))
-    if verbose:
-        print("likely tags: %s" % ",".join(sorted(tags)))
-    for ref in sorted(tags):
-        # sorting will prefer e.g. "2.0" over "2.0rc1"
-        if ref.startswith(tag_prefix):
-            r = ref[len(tag_prefix):]
-            if verbose:
-                print("picking %s" % r)
-            return {"version": r,
-                    "full-revisionid": keywords["full"].strip(),
-                    "dirty": False, "error": None,
-                    "date": date}
-    # no suitable tags, so version is "0+unknown", but full hex is still there
-    if verbose:
-        print("no suitable tags, using unknown + full revision id")
-    return {"version": "0+unknown",
-            "full-revisionid": keywords["full"].strip(),
-            "dirty": False, "error": "no suitable tags", "date": None}
-
-
-@register_vcs_handler("git", "pieces_from_vcs")
-def git_pieces_from_vcs(tag_prefix, root, verbose, run_command=run_command):
-    """Get version from 'git describe' in the root of the source tree.
-
-    This only gets called if the git-archive 'subst' keywords were *not*
-    expanded, and _version.py hasn't already been rewritten with a short
-    version string, meaning we're inside a checked out source tree.
-    """
-    GITS = ["git"]
-    if sys.platform == "win32":
-        GITS = ["git.cmd", "git.exe"]
-
-    out, rc = run_command(GITS, ["rev-parse", "--git-dir"], cwd=root,
-                          hide_stderr=True)
-    if rc != 0:
-        if verbose:
-            print("Directory %s not under git control" % root)
-        raise NotThisMethod("'git rev-parse --git-dir' returned error")
-
-    # if there is a tag matching tag_prefix, this yields TAG-NUM-gHEX[-dirty]
-    # if there isn't one, this yields HEX[-dirty] (no NUM)
-    describe_out, rc = run_command(GITS, ["describe", "--tags", "--dirty",
-                                          "--always", "--long",
-                                          "--match", "%s*" % tag_prefix],
-                                   cwd=root)
-    # --long was added in git-1.5.5
-    if describe_out is None:
-        raise NotThisMethod("'git describe' failed")
-    describe_out = describe_out.strip()
-    full_out, rc = run_command(GITS, ["rev-parse", "HEAD"], cwd=root)
-    if full_out is None:
-        raise NotThisMethod("'git rev-parse' failed")
-    full_out = full_out.strip()
-
-    pieces = {}
-    pieces["long"] = full_out
-    pieces["short"] = full_out[:7]  # maybe improved later
-    pieces["error"] = None
-
-    # parse describe_out. It will be like TAG-NUM-gHEX[-dirty] or HEX[-dirty]
-    # TAG might have hyphens.
-    git_describe = describe_out
-
-    # look for -dirty suffix
-    dirty = git_describe.endswith("-dirty")
-    pieces["dirty"] = dirty
-    if dirty:
-        git_describe = git_describe[:git_describe.rindex("-dirty")]
-
-    # now we have TAG-NUM-gHEX or HEX
-
-    if "-" in git_describe:
-        # TAG-NUM-gHEX
-        mo = re.search(r'^(.+)-(\d+)-g([0-9a-f]+)$', git_describe)
-        if not mo:
-            # unparseable. Maybe git-describe is misbehaving?
-            pieces["error"] = ("unable to parse git-describe output: '%s'"
-                               % describe_out)
-            return pieces
-
-        # tag
-        full_tag = mo.group(1)
-        if not full_tag.startswith(tag_prefix):
-            if verbose:
-                fmt = "tag '%s' doesn't start with prefix '%s'"
-                print(fmt % (full_tag, tag_prefix))
-            pieces["error"] = ("tag '%s' doesn't start with prefix '%s'"
-                               % (full_tag, tag_prefix))
-            return pieces
-        pieces["closest-tag"] = full_tag[len(tag_prefix):]
-
-        # distance: number of commits since tag
-        pieces["distance"] = int(mo.group(2))
-
-        # commit: short hex revision ID
-        pieces["short"] = mo.group(3)
-
-    else:
-        # HEX: no tags
-        pieces["closest-tag"] = None
-        count_out, rc = run_command(GITS, ["rev-list", "HEAD", "--count"],
-                                    cwd=root)
-        pieces["distance"] = int(count_out)  # total number of commits
-
-    # commit date: see ISO-8601 comment in git_versions_from_keywords()
-    date = run_command(GITS, ["show", "-s", "--format=%ci", "HEAD"],
-                       cwd=root)[0].strip()
-    # Use only the last line.  Previous lines may contain GPG signature
-    # information.
-    date = date.splitlines()[-1]
-    pieces["date"] = date.strip().replace(" ", "T", 1).replace(" ", "", 1)
-
-    return pieces
-
-
-def do_vcs_install(manifest_in, versionfile_source, ipy):
-    """Git-specific installation logic for Versioneer.
-
-    For Git, this means creating/changing .gitattributes to mark _version.py
-    for export-subst keyword substitution.
-    """
-    GITS = ["git"]
-    if sys.platform == "win32":
-        GITS = ["git.cmd", "git.exe"]
-    files = [manifest_in, versionfile_source]
-    if ipy:
-        files.append(ipy)
-    try:
-        me = __file__
-        if me.endswith(".pyc") or me.endswith(".pyo"):
-            me = os.path.splitext(me)[0] + ".py"
-        versioneer_file = os.path.relpath(me)
-    except NameError:
-        versioneer_file = "versioneer.py"
-    files.append(versioneer_file)
-    present = False
-    try:
-        f = open(".gitattributes", "r")
-        for line in f.readlines():
-            if line.strip().startswith(versionfile_source):
-                if "export-subst" in line.strip().split()[1:]:
-                    present = True
-        f.close()
-    except EnvironmentError:
-        pass
-    if not present:
-        f = open(".gitattributes", "a+")
-        f.write("%s export-subst\n" % versionfile_source)
-        f.close()
-        files.append(".gitattributes")
-    run_command(GITS, ["add", "--"] + files)
-
-
-def versions_from_parentdir(parentdir_prefix, root, verbose):
-    """Try to determine the version from the parent directory name.
-
-    Source tarballs conventionally unpack into a directory that includes both
-    the project name and a version string. We will also support searching up
-    two directory levels for an appropriately named parent directory
-    """
-    rootdirs = []
-
-    for i in range(3):
-        dirname = os.path.basename(root)
-        if dirname.startswith(parentdir_prefix):
-            return {"version": dirname[len(parentdir_prefix):],
-                    "full-revisionid": None,
-                    "dirty": False, "error": None, "date": None}
-        else:
-            rootdirs.append(root)
-            root = os.path.dirname(root)  # up a level
-
-    if verbose:
-        print("Tried directories %s but none started with prefix %s" %
-              (str(rootdirs), parentdir_prefix))
-    raise NotThisMethod("rootdir doesn't start with parentdir_prefix")
-
-
-SHORT_VERSION_PY = """
-# This file was generated by 'versioneer.py' (0.19) from
-# revision-control system data, or from the parent directory name of an
-# unpacked source archive. Distribution tarballs contain a pre-generated copy
-# of this file.
-
-import json
-
-version_json = '''
-%s
-'''  # END VERSION_JSON
-
-
-def get_versions():
-    return json.loads(version_json)
-"""
-
-
-def versions_from_file(filename):
-    """Try to determine the version from _version.py if present."""
-    try:
-        with open(filename) as f:
-            contents = f.read()
-    except EnvironmentError:
-        raise NotThisMethod("unable to read _version.py")
-    mo = re.search(r"version_json = '''\n(.*)'''  # END VERSION_JSON",
-                   contents, re.M | re.S)
-    if not mo:
-        mo = re.search(r"version_json = '''\r\n(.*)'''  # END VERSION_JSON",
-                       contents, re.M | re.S)
-    if not mo:
-        raise NotThisMethod("no version_json in _version.py")
-    return json.loads(mo.group(1))
-
-
-def write_to_version_file(filename, versions):
-    """Write the given version number to the given _version.py file."""
-    os.unlink(filename)
-    contents = json.dumps(versions, sort_keys=True,
-                          indent=1, separators=(",", ": "))
-    with open(filename, "w") as f:
-        f.write(SHORT_VERSION_PY % contents)
-
-    print("set %s to '%s'" % (filename, versions["version"]))
-
-
-def plus_or_dot(pieces):
-    """Return a + if we don't already have one, else return a ."""
-    if "+" in pieces.get("closest-tag", ""):
-        return "."
-    return "+"
-
-
-def render_pep440(pieces):
-    """Build up version string, with post-release "local version identifier".
-
-    Our goal: TAG[+DISTANCE.gHEX[.dirty]] . Note that if you
-    get a tagged build and then dirty it, you'll get TAG+0.gHEX.dirty
-
-    Exceptions:
-    1: no tags. git_describe was just HEX. 0+untagged.DISTANCE.gHEX[.dirty]
-    """
-    if pieces["closest-tag"]:
-        rendered = pieces["closest-tag"]
-        if pieces["distance"] or pieces["dirty"]:
-            rendered += plus_or_dot(pieces)
-            rendered += "%d.g%s" % (pieces["distance"], pieces["short"])
-            if pieces["dirty"]:
-                rendered += ".dirty"
-    else:
-        # exception #1
-        rendered = "0+untagged.%d.g%s" % (pieces["distance"],
-                                          pieces["short"])
-        if pieces["dirty"]:
-            rendered += ".dirty"
-    return rendered
-
-
-def render_pep440_pre(pieces):
-    """TAG[.post0.devDISTANCE] -- No -dirty.
-
-    Exceptions:
-    1: no tags. 0.post0.devDISTANCE
-    """
-    if pieces["closest-tag"]:
-        rendered = pieces["closest-tag"]
-        if pieces["distance"]:
-            rendered += ".post0.dev%d" % pieces["distance"]
-    else:
-        # exception #1
-        rendered = "0.post0.dev%d" % pieces["distance"]
-    return rendered
-
-
-def render_pep440_post(pieces):
-    """TAG[.postDISTANCE[.dev0]+gHEX] .
-
-    The ".dev0" means dirty. Note that .dev0 sorts backwards
-    (a dirty tree will appear "older" than the corresponding clean one),
-    but you shouldn't be releasing software with -dirty anyways.
-
-    Exceptions:
-    1: no tags. 0.postDISTANCE[.dev0]
-    """
-    if pieces["closest-tag"]:
-        rendered = pieces["closest-tag"]
-        if pieces["distance"] or pieces["dirty"]:
-            rendered += ".post%d" % pieces["distance"]
-            if pieces["dirty"]:
-                rendered += ".dev0"
-            rendered += plus_or_dot(pieces)
-            rendered += "g%s" % pieces["short"]
-    else:
-        # exception #1
-        rendered = "0.post%d" % pieces["distance"]
-        if pieces["dirty"]:
-            rendered += ".dev0"
-        rendered += "+g%s" % pieces["short"]
-    return rendered
-
-
-def render_pep440_old(pieces):
-    """TAG[.postDISTANCE[.dev0]] .
-
-    The ".dev0" means dirty.
-
-    Exceptions:
-    1: no tags. 0.postDISTANCE[.dev0]
-    """
-    if pieces["closest-tag"]:
-        rendered = pieces["closest-tag"]
-        if pieces["distance"] or pieces["dirty"]:
-            rendered += ".post%d" % pieces["distance"]
-            if pieces["dirty"]:
-                rendered += ".dev0"
-    else:
-        # exception #1
-        rendered = "0.post%d" % pieces["distance"]
-        if pieces["dirty"]:
-            rendered += ".dev0"
-    return rendered
-
-
-def render_git_describe(pieces):
-    """TAG[-DISTANCE-gHEX][-dirty].
-
-    Like 'git describe --tags --dirty --always'.
-
-    Exceptions:
-    1: no tags. HEX[-dirty]  (note: no 'g' prefix)
-    """
-    if pieces["closest-tag"]:
-        rendered = pieces["closest-tag"]
-        if pieces["distance"]:
-            rendered += "-%d-g%s" % (pieces["distance"], pieces["short"])
-    else:
-        # exception #1
-        rendered = pieces["short"]
-    if pieces["dirty"]:
-        rendered += "-dirty"
-    return rendered
-
-
-def render_git_describe_long(pieces):
-    """TAG-DISTANCE-gHEX[-dirty].
-
-    Like 'git describe --tags --dirty --always -long'.
-    The distance/hash is unconditional.
-
-    Exceptions:
-    1: no tags. HEX[-dirty]  (note: no 'g' prefix)
-    """
-    if pieces["closest-tag"]:
-        rendered = pieces["closest-tag"]
-        rendered += "-%d-g%s" % (pieces["distance"], pieces["short"])
-    else:
-        # exception #1
-        rendered = pieces["short"]
-    if pieces["dirty"]:
-        rendered += "-dirty"
-    return rendered
-
-
-def render(pieces, style):
-    """Render the given version pieces into the requested style."""
-    if pieces["error"]:
-        return {"version": "unknown",
-                "full-revisionid": pieces.get("long"),
-                "dirty": None,
-                "error": pieces["error"],
-                "date": None}
-
-    if not style or style == "default":
-        style = "pep440"  # the default
-
-    if style == "pep440":
-        rendered = render_pep440(pieces)
-    elif style == "pep440-pre":
-        rendered = render_pep440_pre(pieces)
-    elif style == "pep440-post":
-        rendered = render_pep440_post(pieces)
-    elif style == "pep440-old":
-        rendered = render_pep440_old(pieces)
-    elif style == "git-describe":
-        rendered = render_git_describe(pieces)
-    elif style == "git-describe-long":
-        rendered = render_git_describe_long(pieces)
-    else:
-        raise ValueError("unknown style '%s'" % style)
-
-    return {"version": rendered, "full-revisionid": pieces["long"],
-            "dirty": pieces["dirty"], "error": None,
-            "date": pieces.get("date")}
-
-
-class VersioneerBadRootError(Exception):
-    """The project root directory is unknown or missing key files."""
-
-
-def get_versions(verbose=False):
-    """Get the project version from whatever source is available.
-
-    Returns dict with two keys: 'version' and 'full'.
-    """
-    if "versioneer" in sys.modules:
-        # see the discussion in cmdclass.py:get_cmdclass()
-        del sys.modules["versioneer"]
-
-    root = get_root()
-    cfg = get_config_from_root(root)
-
-    assert cfg.VCS is not None, "please set [versioneer]VCS= in setup.cfg"
-    handlers = HANDLERS.get(cfg.VCS)
-    assert handlers, "unrecognized VCS '%s'" % cfg.VCS
-    verbose = verbose or cfg.verbose
-    assert cfg.versionfile_source is not None, \
-        "please set versioneer.versionfile_source"
-    assert cfg.tag_prefix is not None, "please set versioneer.tag_prefix"
-
-    versionfile_abs = os.path.join(root, cfg.versionfile_source)
-
-    # extract version from first of: _version.py, VCS command (e.g. 'git
-    # describe'), parentdir. This is meant to work for developers using a
-    # source checkout, for users of a tarball created by 'setup.py sdist',
-    # and for users of a tarball/zipball created by 'git archive' or github's
-    # download-from-tag feature or the equivalent in other VCSes.
-
-    get_keywords_f = handlers.get("get_keywords")
-    from_keywords_f = handlers.get("keywords")
-    if get_keywords_f and from_keywords_f:
-        try:
-            keywords = get_keywords_f(versionfile_abs)
-            ver = from_keywords_f(keywords, cfg.tag_prefix, verbose)
-            if verbose:
-                print("got version from expanded keyword %s" % ver)
-            return ver
-        except NotThisMethod:
-            pass
-
-    try:
-        ver = versions_from_file(versionfile_abs)
-        if verbose:
-            print("got version from file %s %s" % (versionfile_abs, ver))
-        return ver
-    except NotThisMethod:
-        pass
-
-    from_vcs_f = handlers.get("pieces_from_vcs")
-    if from_vcs_f:
-        try:
-            pieces = from_vcs_f(cfg.tag_prefix, root, verbose)
-            ver = render(pieces, cfg.style)
-            if verbose:
-                print("got version from VCS %s" % ver)
-            return ver
-        except NotThisMethod:
-            pass
-
-    try:
-        if cfg.parentdir_prefix:
-            ver = versions_from_parentdir(cfg.parentdir_prefix, root, verbose)
-            if verbose:
-                print("got version from parentdir %s" % ver)
-            return ver
-    except NotThisMethod:
-        pass
-
-    if verbose:
-        print("unable to compute version")
-
-    return {"version": "0+unknown", "full-revisionid": None,
-            "dirty": None, "error": "unable to compute version",
-            "date": None}
-
-
-def get_version():
-    """Get the short version string for this project."""
-    return get_versions()["version"]
-
-
-def get_cmdclass(cmdclass=None):
-    """Get the custom setuptools/distutils subclasses used by Versioneer.
-
-    If the package uses a different cmdclass (e.g. one from numpy), it
-    should be provide as an argument.
-    """
-    if "versioneer" in sys.modules:
-        del sys.modules["versioneer"]
-        # this fixes the "python setup.py develop" case (also 'install' and
-        # 'easy_install .'), in which subdependencies of the main project are
-        # built (using setup.py bdist_egg) in the same python process. Assume
-        # a main project A and a dependency B, which use different versions
-        # of Versioneer. A's setup.py imports A's Versioneer, leaving it in
-        # sys.modules by the time B's setup.py is executed, causing B to run
-        # with the wrong versioneer. Setuptools wraps the sub-dep builds in a
-        # sandbox that restores sys.modules to it's pre-build state, so the
-        # parent is protected against the child's "import versioneer". By
-        # removing ourselves from sys.modules here, before the child build
-        # happens, we protect the child from the parent's versioneer too.
-        # Also see https://github.com/python-versioneer/python-versioneer/issues/52
-
-    cmds = {} if cmdclass is None else cmdclass.copy()
-
-    # we add "version" to both distutils and setuptools
-    from distutils.core import Command
-
-    class cmd_version(Command):
-        description = "report generated version string"
-        user_options = []
-        boolean_options = []
-
-        def initialize_options(self):
-            pass
-
-        def finalize_options(self):
-            pass
-
-        def run(self):
-            vers = get_versions(verbose=True)
-            print("Version: %s" % vers["version"])
-            print(" full-revisionid: %s" % vers.get("full-revisionid"))
-            print(" dirty: %s" % vers.get("dirty"))
-            print(" date: %s" % vers.get("date"))
-            if vers["error"]:
-                print(" error: %s" % vers["error"])
-    cmds["version"] = cmd_version
-
-    # we override "build_py" in both distutils and setuptools
-    #
-    # most invocation pathways end up running build_py:
-    #  distutils/build -> build_py
-    #  distutils/install -> distutils/build ->..
-    #  setuptools/bdist_wheel -> distutils/install ->..
-    #  setuptools/bdist_egg -> distutils/install_lib -> build_py
-    #  setuptools/install -> bdist_egg ->..
-    #  setuptools/develop -> ?
-    #  pip install:
-    #   copies source tree to a tempdir before running egg_info/etc
-    #   if .git isn't copied too, 'git describe' will fail
-    #   then does setup.py bdist_wheel, or sometimes setup.py install
-    #  setup.py egg_info -> ?
-
-    # we override different "build_py" commands for both environments
-    if 'build_py' in cmds:
-        _build_py = cmds['build_py']
-    elif "setuptools" in sys.modules:
-        from setuptools.command.build_py import build_py as _build_py
-    else:
-        from distutils.command.build_py import build_py as _build_py
-
-    class cmd_build_py(_build_py):
-        def run(self):
-            root = get_root()
-            cfg = get_config_from_root(root)
-            versions = get_versions()
-            _build_py.run(self)
-            # now locate _version.py in the new build/ directory and replace
-            # it with an updated value
-            if cfg.versionfile_build:
-                target_versionfile = os.path.join(self.build_lib,
-                                                  cfg.versionfile_build)
-                print("UPDATING %s" % target_versionfile)
-                write_to_version_file(target_versionfile, versions)
-    cmds["build_py"] = cmd_build_py
-
-    if "setuptools" in sys.modules:
-        from setuptools.command.build_ext import build_ext as _build_ext
-    else:
-        from distutils.command.build_ext import build_ext as _build_ext
-
-    class cmd_build_ext(_build_ext):
-        def run(self):
-            root = get_root()
-            cfg = get_config_from_root(root)
-            versions = get_versions()
-            _build_ext.run(self)
-            if self.inplace:
-                # build_ext --inplace will only build extensions in
-                # build/lib<..> dir with no _version.py to write to.
-                # As in place builds will already have a _version.py
-                # in the module dir, we do not need to write one.
-                return
-            # now locate _version.py in the new build/ directory and replace
-            # it with an updated value
-            target_versionfile = os.path.join(self.build_lib,
-                                              cfg.versionfile_source)
-            print("UPDATING %s" % target_versionfile)
-            write_to_version_file(target_versionfile, versions)
-    cmds["build_ext"] = cmd_build_ext
-
-    if "cx_Freeze" in sys.modules:  # cx_freeze enabled?
-        from cx_Freeze.dist import build_exe as _build_exe
-        # nczeczulin reports that py2exe won't like the pep440-style string
-        # as FILEVERSION, but it can be used for PRODUCTVERSION, e.g.
-        # setup(console=[{
-        #   "version": versioneer.get_version().split("+", 1)[0], # FILEVERSION
-        #   "product_version": versioneer.get_version(),
-        #   ...
-
-        class cmd_build_exe(_build_exe):
-            def run(self):
-                root = get_root()
-                cfg = get_config_from_root(root)
-                versions = get_versions()
-                target_versionfile = cfg.versionfile_source
-                print("UPDATING %s" % target_versionfile)
-                write_to_version_file(target_versionfile, versions)
-
-                _build_exe.run(self)
-                os.unlink(target_versionfile)
-                with open(cfg.versionfile_source, "w") as f:
-                    LONG = LONG_VERSION_PY[cfg.VCS]
-                    f.write(LONG %
-                            {"DOLLAR": "$",
-                             "STYLE": cfg.style,
-                             "TAG_PREFIX": cfg.tag_prefix,
-                             "PARENTDIR_PREFIX": cfg.parentdir_prefix,
-                             "VERSIONFILE_SOURCE": cfg.versionfile_source,
-                             })
-        cmds["build_exe"] = cmd_build_exe
-        del cmds["build_py"]
-
-    if 'py2exe' in sys.modules:  # py2exe enabled?
-        from py2exe.distutils_buildexe import py2exe as _py2exe
-
-        class cmd_py2exe(_py2exe):
-            def run(self):
-                root = get_root()
-                cfg = get_config_from_root(root)
-                versions = get_versions()
-                target_versionfile = cfg.versionfile_source
-                print("UPDATING %s" % target_versionfile)
-                write_to_version_file(target_versionfile, versions)
-
-                _py2exe.run(self)
-                os.unlink(target_versionfile)
-                with open(cfg.versionfile_source, "w") as f:
-                    LONG = LONG_VERSION_PY[cfg.VCS]
-                    f.write(LONG %
-                            {"DOLLAR": "$",
-                             "STYLE": cfg.style,
-                             "TAG_PREFIX": cfg.tag_prefix,
-                             "PARENTDIR_PREFIX": cfg.parentdir_prefix,
-                             "VERSIONFILE_SOURCE": cfg.versionfile_source,
-                             })
-        cmds["py2exe"] = cmd_py2exe
-
-    # we override different "sdist" commands for both environments
-    if 'sdist' in cmds:
-        _sdist = cmds['sdist']
-    elif "setuptools" in sys.modules:
-        from setuptools.command.sdist import sdist as _sdist
-    else:
-        from distutils.command.sdist import sdist as _sdist
-
-    class cmd_sdist(_sdist):
-        def run(self):
-            versions = get_versions()
-            self._versioneer_generated_versions = versions
-            # unless we update this, the command will keep using the old
-            # version
-            self.distribution.metadata.version = versions["version"]
-            return _sdist.run(self)
-
-        def make_release_tree(self, base_dir, files):
-            root = get_root()
-            cfg = get_config_from_root(root)
-            _sdist.make_release_tree(self, base_dir, files)
-            # now locate _version.py in the new base_dir directory
-            # (remembering that it may be a hardlink) and replace it with an
-            # updated value
-            target_versionfile = os.path.join(base_dir, cfg.versionfile_source)
-            print("UPDATING %s" % target_versionfile)
-            write_to_version_file(target_versionfile,
-                                  self._versioneer_generated_versions)
-    cmds["sdist"] = cmd_sdist
-
-    return cmds
-
-
-CONFIG_ERROR = """
-setup.cfg is missing the necessary Versioneer configuration. You need
-a section like:
-
- [versioneer]
- VCS = git
- style = pep440
- versionfile_source = src/myproject/_version.py
- versionfile_build = myproject/_version.py
- tag_prefix =
- parentdir_prefix = myproject-
-
-You will also need to edit your setup.py to use the results:
-
- import versioneer
- setup(version=versioneer.get_version(),
-       cmdclass=versioneer.get_cmdclass(), ...)
-
-Please read the docstring in ./versioneer.py for configuration instructions,
-edit setup.cfg, and re-run the installer or 'python versioneer.py setup'.
-"""
-
-SAMPLE_CONFIG = """
-# See the docstring in versioneer.py for instructions. Note that you must
-# re-run 'versioneer.py setup' after changing this section, and commit the
-# resulting files.
-
-[versioneer]
-#VCS = git
-#style = pep440
-#versionfile_source =
-#versionfile_build =
-#tag_prefix =
-#parentdir_prefix =
-
-"""
-
-INIT_PY_SNIPPET = """
-from ._version import get_versions
-__version__ = get_versions()['version']
-del get_versions
-"""
-
-
-def do_setup():
-    """Do main VCS-independent setup function for installing Versioneer."""
-    root = get_root()
-    try:
-        cfg = get_config_from_root(root)
-    except (EnvironmentError, configparser.NoSectionError,
-            configparser.NoOptionError) as e:
-        if isinstance(e, (EnvironmentError, configparser.NoSectionError)):
-            print("Adding sample versioneer config to setup.cfg",
-                  file=sys.stderr)
-            with open(os.path.join(root, "setup.cfg"), "a") as f:
-                f.write(SAMPLE_CONFIG)
-        print(CONFIG_ERROR, file=sys.stderr)
-        return 1
-
-    print(" creating %s" % cfg.versionfile_source)
-    with open(cfg.versionfile_source, "w") as f:
-        LONG = LONG_VERSION_PY[cfg.VCS]
-        f.write(LONG % {"DOLLAR": "$",
-                        "STYLE": cfg.style,
-                        "TAG_PREFIX": cfg.tag_prefix,
-                        "PARENTDIR_PREFIX": cfg.parentdir_prefix,
-                        "VERSIONFILE_SOURCE": cfg.versionfile_source,
-                        })
-
-    ipy = os.path.join(os.path.dirname(cfg.versionfile_source),
-                       "__init__.py")
-    if os.path.exists(ipy):
-        try:
-            with open(ipy, "r") as f:
-                old = f.read()
-        except EnvironmentError:
-            old = ""
-        if INIT_PY_SNIPPET not in old:
-            print(" appending to %s" % ipy)
-            with open(ipy, "a") as f:
-                f.write(INIT_PY_SNIPPET)
-        else:
-            print(" %s unmodified" % ipy)
-    else:
-        print(" %s doesn't exist, ok" % ipy)
-        ipy = None
-
-    # Make sure both the top-level "versioneer.py" and versionfile_source
-    # (PKG/_version.py, used by runtime code) are in MANIFEST.in, so
-    # they'll be copied into source distributions. Pip won't be able to
-    # install the package without this.
-    manifest_in = os.path.join(root, "MANIFEST.in")
-    simple_includes = set()
-    try:
-        with open(manifest_in, "r") as f:
-            for line in f:
-                if line.startswith("include "):
-                    for include in line.split()[1:]:
-                        simple_includes.add(include)
-    except EnvironmentError:
-        pass
-    # That doesn't cover everything MANIFEST.in can do
-    # (http://docs.python.org/2/distutils/sourcedist.html#commands), so
-    # it might give some false negatives. Appending redundant 'include'
-    # lines is safe, though.
-    if "versioneer.py" not in simple_includes:
-        print(" appending 'versioneer.py' to MANIFEST.in")
-        with open(manifest_in, "a") as f:
-            f.write("include versioneer.py\n")
-    else:
-        print(" 'versioneer.py' already in MANIFEST.in")
-    if cfg.versionfile_source not in simple_includes:
-        print(" appending versionfile_source ('%s') to MANIFEST.in" %
-              cfg.versionfile_source)
-        with open(manifest_in, "a") as f:
-            f.write("include %s\n" % cfg.versionfile_source)
-    else:
-        print(" versionfile_source already in MANIFEST.in")
-
-    # Make VCS-specific changes. For git, this means creating/changing
-    # .gitattributes to mark _version.py for export-subst keyword
-    # substitution.
-    do_vcs_install(manifest_in, cfg.versionfile_source, ipy)
-    return 0
-
-
-def scan_setup_py():
-    """Validate the contents of setup.py against Versioneer's expectations."""
-    found = set()
-    setters = False
-    errors = 0
-    with open("setup.py", "r") as f:
-        for line in f.readlines():
-            if "import versioneer" in line:
-                found.add("import")
-            if "versioneer.get_cmdclass()" in line:
-                found.add("cmdclass")
-            if "versioneer.get_version()" in line:
-                found.add("get_version")
-            if "versioneer.VCS" in line:
-                setters = True
-            if "versioneer.versionfile_source" in line:
-                setters = True
-    if len(found) != 3:
-        print("")
-        print("Your setup.py appears to be missing some important items")
-        print("(but I might be wrong). Please make sure it has something")
-        print("roughly like the following:")
-        print("")
-        print(" import versioneer")
-        print(" setup( version=versioneer.get_version(),")
-        print("        cmdclass=versioneer.get_cmdclass(),  ...)")
-        print("")
-        errors += 1
-    if setters:
-        print("You should remove lines like 'versioneer.VCS = ' and")
-        print("'versioneer.versionfile_source = ' . This configuration")
-        print("now lives in setup.cfg, and should be removed from setup.py")
-        print("")
-        errors += 1
-    return errors
-
-
-if __name__ == "__main__":
-    cmd = sys.argv[1]
-    if cmd == "setup":
-        errors = do_setup()
-        errors += scan_setup_py()
-        if errors:
-            sys.exit(1)