diff --git a/src/lbmpy/creationfunctions.py b/src/lbmpy/creationfunctions.py
index 467c9a40ba3126a1d9bf3fa01a804c1797342665..827e442f91bcedf3ab76d74b38bb49e3a8b42e74 100644
--- a/src/lbmpy/creationfunctions.py
+++ b/src/lbmpy/creationfunctions.py
@@ -67,7 +67,8 @@ from lbmpy.enums import Stencil, Method, ForceModel, CollisionSpace, SubgridScal
 import lbmpy.forcemodels as forcemodels
 from lbmpy.fieldaccess import CollideOnlyInplaceAccessor, PdfFieldAccessor, PeriodicTwoFieldsAccessor
 from lbmpy.fluctuatinglb import add_fluctuations_to_collision_rule
-from lbmpy.partially_saturated_cells import (replace_by_psm_collision_rule, PSMConfig, add_psm_solid_collision_to_collision_rule)
+from lbmpy.partially_saturated_cells import (replace_by_psm_collision_rule, PSMConfig,
+                                             add_psm_solid_collision_to_collision_rule)
 from lbmpy.non_newtonian_models import add_cassons_model, CassonsParameters
 from lbmpy.methods import (create_mrt_orthogonal, create_mrt_raw, create_central_moment,
                            create_srt, create_trt, create_trt_kbc)
diff --git a/src/lbmpy/partially_saturated_cells.py b/src/lbmpy/partially_saturated_cells.py
index a3ef4fdb43bf5aa534e100fb9fd783148d5e9432..963d55a2c6416d1226eb48f14989d8a196a7126c 100644
--- a/src/lbmpy/partially_saturated_cells.py
+++ b/src/lbmpy/partially_saturated_cells.py
@@ -53,7 +53,7 @@ def get_psm_solid_collision_term(collision_rule, psm_config, particle_per_cell_c
     equilibrium_fluid = method.get_equilibrium_terms()
     equilibrium_solid = []
 
-    #get equilibrium form object velocity
+    # get equilibrium form object velocity
     for eq in equilibrium_fluid:
         eq_sol = eq
         for i in range(stencil.D):
@@ -66,26 +66,17 @@ def get_psm_solid_collision_term(collision_rule, psm_config, particle_per_cell_c
             zip(equilibrium_fluid, equilibrium_solid, pre_collision_pdf_symbols, stencil)):
         inverse_direction_index = stencil.stencil_entries.index(stencil.inverse_stencil_entries[i])
         if psm_config.solid_collision == 1:
-            solid_collision = fraction_field.center(particle_per_cell_counter) * (
-                    (
-                            pre_collision_pdf_symbols[inverse_direction_index]
-                            - equilibrium_fluid[inverse_direction_index]
-                    )
-                    - (f - eqSolid)
-            )
+            solid_collision = (fraction_field.center(particle_per_cell_counter)
+                               * ((pre_collision_pdf_symbols[inverse_direction_index]
+                                   - equilibrium_fluid[inverse_direction_index]) - (f - eqSolid)))
         elif psm_config.solid_collision == 2:
             # TODO get relaxation rate vector from method and use the right relaxation rate [i]
-            solid_collision = fraction_field.center(particle_per_cell_counter) * (
-                    (eqSolid - f) + (1.0 - method.relaxation_rates[0]) * (f - eqFluid)
-            )
+            solid_collision = (fraction_field.center(particle_per_cell_counter)
+                               * ((eqSolid - f) + (1.0 - method.relaxation_rates[0]) * (f - eqFluid)))
         elif psm_config.solid_collision == 3:
-            solid_collision = fraction_field.center(particle_per_cell_counter) * (
-                    (
-                            pre_collision_pdf_symbols[inverse_direction_index]
-                            - equilibrium_solid[inverse_direction_index]
-                    )
-                    - (f - eqSolid)
-            )
+            solid_collision = (fraction_field.center(particle_per_cell_counter)
+                               * ((pre_collision_pdf_symbols[inverse_direction_index]
+                                   - equilibrium_solid[inverse_direction_index]) - (f - eqSolid)))
         else:
             raise ValueError("Only sc=1, sc=2 and sc=3 are supported.")
 
@@ -101,11 +92,9 @@ def get_psm_force_from_solid_collision(solid_collisions, stencil, object_force_f
         for sc, offset in zip(solid_collisions, stencil):
             forces_rhs -= sc * int(offset[d])
 
-        force_assignments.append( Assignment(
-            object_force_field.center( particle_per_cell_counter * stencil.D + d ), forces_rhs
+        force_assignments.append(Assignment(
+            object_force_field.center(particle_per_cell_counter * stencil.D + d), forces_rhs
         ))
-
-
     return AssignmentCollection(force_assignments)
 
 
@@ -138,7 +127,8 @@ def replace_by_psm_collision_rule(collision_rule, psm_config):
         solid_collisions[p] = get_psm_solid_collision_term(collision_rule, psm_config, p)
 
         if psm_config.object_force_field is not None:
-            collision_assignments += get_psm_force_from_solid_collision(solid_collisions[p], method.stencil, psm_config.object_force_field, p)
+            collision_assignments += get_psm_force_from_solid_collision(solid_collisions[p], method.stencil,
+                                                                        psm_config.object_force_field, p)
 
     for i, main in enumerate(collision_rule.main_assignments):
         rhs = main.rhs