MNT: make the tests easier to read

tacaswell · tacaswell · commit 1b9e6a60665f · 2019-09-18T15:08:30.000+02:00
diff --git a/lib/matplotlib/cm.py b/lib/matplotlib/cm.py
@@ -27,6 +27,7 @@
 from matplotlib._cm_listed import cmaps as cmaps_listed
 from matplotlib.cbook import _warn_external
 
+
 def _reverser(f, x):  # Deprecated, remove this at the same time as revcmap.
     return f(1 - x)  # Toplevel helper for revcmap ensuring cmap picklability.
 
@@ -173,6 +174,7 @@ class ScalarMappable:
     RGBA colors from the given colormap.
 
     """
+
     def __init__(self, norm=None, cmap=None):
         """
 
diff --git a/lib/matplotlib/tests/test_cm.py b/lib/matplotlib/tests/test_cm.py
@@ -2,26 +2,27 @@
 import warnings
 import pytest
 
+
 def test_double_register_cmap():
     with pytest.raises(ValueError):
-        mcm.register_cmap('viridis', mcm.get_cmap('viridis'))
+        mcm.register_cmap("viridis", mcm.get_cmap("viridis"))
 
 
 def test_register_cmap():
-    mcm.register_cmap('viridis'[::-1], mcm.get_cmap('viridis'))
-    assert mcm.get_cmap('viridis'[::-1]) is mcm.get_cmap('viridis')
+    target = "viridis"[::-1]
+    mcm.register_cmap(target, mcm.get_cmap("viridis"))
+    assert mcm.get_cmap(target) is mcm.get_cmap("viridis")
 
     with pytest.warns(UserWarning):
-        mcm.register_cmap('viridis'[::-1], mcm.get_cmap('viridis'))
-
+        mcm.register_cmap(target, mcm.get_cmap("viridis"))
 
-    mcm.unregister_cmap('viridis'[::-1])
+    mcm.unregister_cmap(target)
     with pytest.raises(ValueError):
-        mcm.get_cmap('viridis'[::-1])
+        mcm.get_cmap(target)
     # test that second time is error free
-    mcm.unregister_cmap('viridis'[::-1])
+    mcm.unregister_cmap(target)
 
 
 def test_unregister_cmap():
     with pytest.raises(ValueError):
-        mcm.unregister_cmap('viridis')
+        mcm.unregister_cmap("viridis")
