python - 根据比较条件将值插入数据帧

Question

我正在尝试根据与另一个数据帧的比较将值插入到数据帧中。
下面是一个例子:

>>> import pandas as pd
>>> import numpy as np
>>> print(df)
>>> df
      name                          
  0  richard Finn, Tim Maltby       
  1  Fernando Lebrija                          

>>> df2

       Fullname             id
  0   richard Finn          500
  1   Tim Maltby            699
  2   Fernando Lebrija      300

所需的输出是:

 >>> df
      name                            id              
  0  richard Finn, Tim Maltby        500,699
  1  Fernando Lebrija                300

我尝试使用:

df['id'] = np.where((df['name']==df2['Fullname']), df2['id]', df['id'])

但它给了我以下错误:
`语法错误:语法无效

Answer 1

您可以进行拆分，爆炸，然后映射和分组:

df['id'] = (df['name'].str.split(',\s*')
    .explode()
    .map(df2.set_index('Fullname')['id'])
    .groupby(level=0).agg(list)
)

输出:

                       name          id
0  richard Finn, Tim Maltby  [500, 699]
1          Fernando Lebrija       [300]