Pandas - Get values within parentheses of a panda dataframe column [duplicate]

问题

This question already has an answer here:

Copy text between parentheses in pandas DataFrame column into another column (1 answer)

Closed 18 days ago.

My df has 2 columns:

Name    Attr
a(bc)
b(aca)
(cba)

I would like the column Attr to have the values within parentheses of column Name

Name    Attr
a(bc)   bc
b(aca)  aca
(cba)   cba

I tried:

df['Attr'] = re.findall('\(.*?\)',df['Name'].astype('str'))

TypeError: expected string or buffer

Really appreciate any help

回答1:

Use str.extract:

df['Attr'] = df['Name'].str.extract(r"\(([A-Za-z]+)\)", expand=False)
print (df)
     Name Attr
0   a(bc)   bc
1  b(aca)  aca
2   (cba)  cba

Or add () to your regex:

df['Attr'] = df['Name'].str.extract(r"\((.*?)\)", expand=False)
print (df)
     Name Attr
0   a(bc)   bc
1  b(aca)  aca
2   (cba)  cba

来源：https://stackoverflow.com/questions/37920443/pandas-get-values-within-parentheses-of-a-panda-dataframe-column