BUG: return ax.get_figure() in scatter_plot if ax argument is not None

Author: Chang She

pandas/tools/plotting.py

@@ -705,6 +705,8 @@ def plot_group(group, ax):
         if ax is None:
             fig = plt.figure()
             ax = fig.add_subplot(111)
+        else:
+            fig = ax.get_figure()
         plot_group(data, ax)
         ax.set_ylabel(str(y))
         ax.set_xlabel(str(x))