定义列系列的一部分以在 pandas 中建立索引

Question

import pandas as pd 
data = {'col': ['a11 aaa','a121 aaaa','a3333 adfdf']}
df = pd.DataFrame(data)

我想设置索引类似['a11','a121','a3333']

print(df)

Answer 1

选项 1

import pandas as pd 
data = {'col': ['a11 aaa','a121 aaaa','a3333 adfdf']}
df = pd.DataFrame(data)

df.index = df['col'].apply(lambda line: line.split(' ')[0]).tolist()
df

选项 2

import pandas as pd 
data = {'col': ['a11 aaa','a121 aaaa','a3333 adfdf']}
indexes = map(lambda line: line.split(' ')[0],data['col'])
df = pd.DataFrame(data,index=indexes)

df

输出

      |  col
a11   | a11 aaa
a121  | a121 aaaa
a3333 | a3333 adfdf