正则表达式PANDAS数据框

Question

我有一个看起来像这样的数据框：

import pandas as pd

df= pd.DataFrame({'type':['-','L1iability','-','Liability1','-'],'Amount':[10,-10,20,-20,5]})
df

我想用“ 3rd”替换类型列中除“-”以外的所有内容。如何使用replace命令和regex做到这一点？

Answer 1

IIUC mask

df['3rdcol']=df.type.mask(~(df.type=='-'),'Liability1')
df
Out[303]: 
   Amount        type      3rdcol
0      10           -           -
1     -10  L1iability  Liability1
2      20           -           -
3     -20  Liability1  Liability1
4       5           -           -