Plot: convert 'c' to 'color' immediately; closes matplotlib#4162, matplotlib#4157

Author: efiring

lib/matplotlib/axes/_axes.py

@@ -1366,6 +1366,12 @@ def plot(self, *args, **kwargs):
             self.cla()
         lines = []
 
+        # Convert "c" alias to "color" immediately, to avoid
+        # confusion farther on.
+        c = kwargs.pop('c', None)
+        if c is not None:
+            kwargs['color'] = c
+
         for line in self._get_lines(*args, **kwargs):
             self.add_line(line)
             lines.append(line)

lib/matplotlib/tests/test_axes.py

@@ -3492,10 +3492,10 @@ def test_set_get_ticklabels():
     # set ticklabel to 1 plot in normal way
     ax[0].set_xticklabels(('a', 'b', 'c', 'd'))
     ax[0].set_yticklabels(('11', '12', '13', '14'))
-   
+
     # set ticklabel to the other plot, expect the 2 plots have same label setting
-    # pass get_ticklabels return value as ticklabels argument    
-    ax[1].set_xticklabels(ax[0].get_xticklabels() ) 
+    # pass get_ticklabels return value as ticklabels argument
+    ax[1].set_xticklabels(ax[0].get_xticklabels() )
     ax[1].set_yticklabels(ax[0].get_yticklabels() )
 
 
@@ -3545,11 +3545,18 @@ def test_color_None():
     fig, ax = plt.subplots()
     ax.plot([1,2], [1,2], color=None)
 
+@cleanup
+def test_color_alias():
+    # issues 4157 and 4162
+    fig, ax = plt.subplots()
+    line = ax.plot([0, 1], c='lime')[0]
+    assert_equal('lime', line.get_color())
+
 @cleanup
 def test_numerical_hist_label():
     fig, ax = plt.subplots()
     ax.hist([range(15)] * 5, label=range(5))
-    
+
 @cleanup
 def test_move_offsetlabel():
     data = np.random.random(10) * 1e-22