API: Add DataFrame.droplevel

pandas/core/frame.py

@@ -4630,6 +4630,63 @@ def sortlevel(self, level=0, axis=0, ascending=True, inplace=False,
         return self.sort_index(level=level, axis=axis, ascending=ascending,
                                inplace=inplace, sort_remaining=sort_remaining)
 
+    def droplevel(self, level, axis=0):
+        """Return DataFrame with requested index / column level(s) removed.
+
+        Parameters
+        ----------
+        level : int, str, or list-like
+            If a string is given, must be the name of a level
+            If list-like, elements must be names or indexes of levels.
+
+        axis : {0 or 'index', 1 or 'columns'}, default 0
+
+        .. versionadded:: 0.24.0
+
+        Returns
+        -------
+        DataFrame.droplevel()
+
+        Examples
+        --------
+        >>> df = pd.DataFrame([
+        ...:     [1, 2, 3, 4],
+        ...:     [5, 6, 7, 8],
+        ...:     [9, 10, 11, 12]
+        ...: ]).set_index([0, 1]).rename_axis(['a', 'b'])
+        >>> df.columns = pd.MultiIndex.from_tuples([
+        ...:    ('c', 'e'), ('d', 'f')
+        ...:], names=['level_1', 'level_2'])
+        >>> df
+        level_1   c   d
+        level_2   e   f
+        a b
+        1 2      3   4
+        5 6      7   8
+        9 10    11  12
+        >>> df.droplevel('a')
+        level_1   c   d
+        level_2   e   f
+        b
+        2        3   4
+        6        7   8
+        10      11  12
+        >>> df.droplevel('level2', axis=1)
+        level_1   c   d
+        a b
+        1 2      3   4
+        5 6      7   8
+        9 10    11  12
+
+        """
+        result = self.copy()
+        axis = self._get_axis_number(axis)
+        if axis == 0:
+            result.index = result.index.droplevel(level)
+        else:
+            result.columns = result.columns.droplevel(level)
+        return result
+
     def nlargest(self, n, columns, keep='first'):
         """
         Return the first `n` rows ordered by `columns` in descending order.

pandas/tests/frame/test_alter_axes.py

@@ -1056,6 +1056,30 @@ def test_reindex_signature(self):
                               "limit", "copy", "level", "method",
                               "fill_value", "tolerance"}
 
+    def test_droplevel(self):
+        df = pd.DataFrame([
+            [1, 2, 3, 4],
+            [5, 6, 7, 8],
+            [9, 10, 11, 12]
+        ])
+        df = df.set_index([0, 1]).rename_axis(['a', 'b'])
+        df.columns = pd.MultiIndex.from_tuples([('c', 'e'), ('d', 'f')],
+                                               names=['level_1', 'level_2'])
+
+        # test that dropping of a level in the index works
+        expected_df_no_level_a_in_index = df.reset_index('a', drop=True)
+        actual_df_no_level_a_in_index = df.droplevel('a')
+        assert_frame_equal(expected_df_no_level_a_in_index,
+                           actual_df_no_level_a_in_index)
+
+        # test that dropping of a level in the index works
+        expected_df_no_level_2_in_columns = df.copy()
+        expected_df_no_level_2_in_columns.columns = pd.Index(['c', 'd'],
+                                                             name='level_1')
+        actual_df_no_level_2_in_columns = df.droplevel('level_2', axis=1)
+        assert_frame_equal(expected_df_no_level_2_in_columns,
+                           actual_df_no_level_2_in_columns)
+
 
 class TestIntervalIndex(object):