希望收集相同的标题字符串

Question

我将页眉设置为

'''
+--------------+------------------+----------------+--------------+---------------+
| usa_alaska   | usa_california   | france_paris   | italy_roma   | france_lyon   |
|--------------+------------------+----------------+--------------+---------------|
+--------------+------------------+----------------+--------------+---------------+
'''
df = pd.DataFrame([], columns = 'usa_alaska  usa_california  france_paris  italy_roma  france_lyon'.split())

我想按国家和地区分开标题，这样当我调用france时，我应该得到paris和lyon作为列。

Answer 1

从列名创建MultiIndex:

假设这个数据帧:

>>> df
usa_alaska  usa_california  france_paris  italy_roma  france_lyon
0           1               2             3           4            5

df.columns = df.columns.str.split('_', expand=True)
df = df.sort_index(axis=1)

输出

>>> df
france       italy    usa           
lyon paris  roma alaska california
0      5     3     4      1          2
>>> df['france']
paris  lyon
0      3     5