give default directly

only Colormap object caused problem (tab completion triggered '__repr__'
which means showing colormap in maplotlib window

python/damask/_grid.py

@@ -688,7 +688,7 @@ class Grid:
 
 
     def show(self,
-             colormap: Union[Colormap, str] = None) -> None:
+             colormap: Union[Colormap, str] = 'cividis') -> None:
         """
         Show on screen.
 

python/damask/_vtk.py

@@ -503,7 +503,7 @@ class VTK:
 
     def show(self,
              label: str = None,
-             colormap: Union[Colormap, str] = None):
+             colormap: Union[Colormap, str] = 'cividis'):
         """
         Render.
 
@@ -516,7 +516,7 @@ class VTK:
 
         Notes
         -----
-           See http://compilatrix.com/article/vtk-1 for further ideas.
+            See http://compilatrix.com/article/vtk-1 for further ideas.
 
         """
         try:
@@ -535,9 +535,8 @@ class VTK:
                 height =  768
 
         lut = vtk.vtkLookupTable()
-        colormap_ = Colormap.from_predefined('cividis') if colormap is None \
-               else Colormap.from_predefined(colormap) if isinstance(colormap,str) \
-               else colormap
+        colormap_ = Colormap.from_predefined(colormap) if isinstance(colormap,str) else \
+                    colormap
         lut.SetNumberOfTableValues(len(colormap_.colors))
         for i,c in enumerate(colormap_.colors):
             lut.SetTableValue(i,c if len(c)==4 else np.append(c,1.0))

python/tests/test_Grid.py

@@ -43,7 +43,7 @@ class TestGrid:
         print('patched datetime.datetime.now')
 
 
-    @pytest.mark.parametrize('cmap',[Colormap.from_predefined('cividis'),'cividis',None])
+    @pytest.mark.parametrize('cmap',[Colormap.from_predefined('stress'),'viridis'])
     def test_show(sef,default,cmap,monkeypatch):
         monkeypatch.delenv('DISPLAY',raising=False)
         default.show(cmap)

python/tests/test_VTK.py

@@ -30,7 +30,7 @@ class TestVTK:
     def _patch_execution_stamp(self, patch_execution_stamp):
         print('patched damask.util.execution_stamp')
 
-    @pytest.mark.parametrize('cmap',[Colormap.from_predefined('cividis'),'cividis',None])
+    @pytest.mark.parametrize('cmap',[Colormap.from_predefined('cividis'),'strain'])
     def test_show(sef,default,cmap,monkeypatch):
         monkeypatch.delenv('DISPLAY',raising=False)
         default.show(colormap=cmap)