API: Remove dashed line in bar plots

Author: TomAugspurger

doc/source/whatsnew/v0.16.0.txt

@@ -49,6 +49,10 @@ Backwards incompatible API changes
 - ``TimedeltaIndex.freqstr`` now output the same string format as ``DatetimeIndex``. (:issue:`9116`)
 
 
+- Bar and horizontal bar plots no longer add a dashed line along the info axis.
+The prior style can be achieved with matplotlib's `axhline` or `axvline`
+methods (:issue:`9088`).
+
 Deprecations
 ~~~~~~~~~~~~
 

pandas/tools/plotting.py

@@ -1895,16 +1895,13 @@ def _post_plot_logic(self):
                 ax.set_xlim((s_edge, e_edge))
                 ax.set_xticks(self.tick_pos)
                 ax.set_xticklabels(str_index)
-                if not self.log: # GH3254+
-                    ax.axhline(0, color='k', linestyle='--')
                 if name is not None and self.use_index:
                     ax.set_xlabel(name)
             elif self.kind == 'barh':
                 # horizontal bars
                 ax.set_ylim((s_edge, e_edge))
                 ax.set_yticks(self.tick_pos)
                 ax.set_yticklabels(str_index)
-                ax.axvline(0, color='k', linestyle='--')
                 if name is not None and self.use_index:
                     ax.set_ylabel(name)
             else: