Extract all numeric characters from a pandas series (all groups)

Question

I am trying to use the str.extract(\'(\\d+)\') method on a pandas series to get the digits of a phone number that looks like: (123) 456-7890

Using this method only r

Answer 1

df = pd.DataFrame({'no': ['(123) 456-7890', '+321 / 555-7890']})
df['clean'] = df.no.str.extractall('(\d+)').unstack().apply(''.join, axis=1)

Result:

    no              clean
0   (123) 456-7890  1234567890
1   +321 / 555-7890 3215557890