Merge pull request #8249 from TomAugspurger/color-cycle

BUG: plot methods modified rcParams

Author: Tom Augspurger

doc/source/v0.15.0.txt

@@ -794,6 +794,6 @@ needed interpolating (:issue:`7173`).
   (:issue:`8230`).
 - Bug with ``DatetimeIndex.asof`` incorrectly matching partial strings and
 returning the wrong date (:issue:`8245`).
-
-
+- Bug in plotting methods modifying the global matplotlib
+rcParams (:issue:`8242`).
 

pandas/tests/test_graphics.py

@@ -479,6 +479,12 @@ def test_plot_figsize_and_title(self):
         self._check_text_labels(ax.title, 'Test')
         self._check_axes_shape(ax, axes_num=1, layout=(1, 1), figsize=(16, 8))
 
+    def test_dont_modify_rcParams(self):
+        # GH 8242
+        colors = self.plt.rcParams['axes.color_cycle']
+        Series([1, 2, 3]).plot()
+        self.assertEqual(colors, self.plt.rcParams['axes.color_cycle'])
+
     def test_ts_line_lim(self):
         ax = self.ts.plot()
         xmin, xmax = ax.get_xlim()

pandas/tools/plotting.py

@@ -116,7 +116,10 @@ def _get_standard_colors(num_colors=None, colormap=None, color_type='default',
         colors = color
     else:
         if color_type == 'default':
-            colors = plt.rcParams.get('axes.color_cycle', list('bgrcmyk'))
+            # need to call list() on the result to copy so we don't
+            # modify the global rcParams below
+            colors = list(plt.rcParams.get('axes.color_cycle',
+                                           list('bgrcmyk')))
             if isinstance(colors, compat.string_types):
                 colors = list(colors)
         elif color_type == 'random':