DataFrame.droplevel

函数定义

DataFrame.droplevel(level, axis=0)
Return Series/DataFrame with requested index / column level(s) removed.

函数参数

• 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 positional indexes of levels.
• axis：{0 or ‘index’, 1 or ‘columns’}, default 0
  Axis along which the level(s) is removed:
  • 0 or 'index': remove level(s) in column.
  • 1 or 'columns': remove level(s) in row.
• Returns：Series/DataFrame
  Series/DataFrame with requested index / column level(s) removed.

例子

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('level_2', axis=1)
level_1   c   d
a b
1 2      3   4
5 6      7   8
9 10    11  12