change pie chart default shape to circular (instead of oval)

jerrylui803 · jerrylui803 · commit 369842bb6047 · 2018-03-21T22:46:58.000-04:00
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -2674,6 +2674,8 @@ def pie(self, x, explode=None, labels=None, colors=None,
         The pie chart will probably look best if the figure and axes are
         square, or the Axes aspect is equal.
         """
+        self.set_aspect('equal')
+
         x = np.array(x, np.float32)
 
         sx = x.sum()
