Add DataTransfer.__str__, Swap.__str__

pystencils/datahandling/graph_datahandling.py

@@ -42,6 +42,9 @@ class DataTransfer:
         self.field = field
         self.kind = kind
 
+    def __str__(self):
+        return f'DataTransferKind: {self.kind} with {self.field}'
+
 
 class Swap(DataTransfer):
     def __init__(self, source, destination, gpu):
@@ -49,6 +52,9 @@ class Swap(DataTransfer):
         self.field = source
         self.destination = destination
 
+    def __str__(self):
+        return f'Swap: {self.field} with {self.destination}'
+
 
 class Communication(DataTransfer):
     def __init__(self, field, stencil, gpu):