pep 8 fixes

Author: mroeschke

Diff for: pandas/tools/tests/test_pivot.py

@@ -350,7 +350,7 @@ def _check_output(result, values_col, index=['A', 'B'],
         # no rows
         rtable = self.data.pivot_table(columns=['AA', 'BB'], margins=True,
                                        aggfunc=np.mean)
-        expected = self.data.groupby(['AA','BB']).mean()
+        expected = self.data.groupby(['AA', 'BB']).mean()
         expected.loc[('All', ''), :] = self.data[['DD', 'EE', 'FF']].mean()
         expected = (expected.stack()
                             .unstack(['BB', 'AA'])