Pandas 根据条件创建新列

Question

我有这样一个Pandas Dataframe:

index   col1     col2  

1       [1,2]    [apple, peer, oragne, banana]  
2       [2]      [pancake, soda]

我想创建一个新列，根据col1的index来选择col2的item，
例如：

index   col1     col2                                   col3

1       [1,2]    [apple, peer, oragne, banana]  [apple,peer]  
2       [2]      [pancake, soda]                         [soda]

请问应该如何操作？

Answer 1

clo3=[]
for i in range(data.shape[0]):
tmp=[]
for j in data['col1'][i]:
tmp.append(data['col2'][i][j-1])
col3.append(tmp)
data['col3']=col3