如果满足特定条件，则替换字符串中的字符

Question

I need to filter Phone numbers "where 1 character is equal to 8 and length is equal to 11" and if my condition is True, I want to change 1 character of filtered Phone numbers from '8' to '7'.

My code is not working properly...

Here is a sample:

import pandas as pd
        
df = pd.DataFrame({"Phone" :['+77013655566','87014324366','7014324366','11111','999999','43434343', '8020556612', '+77015452313','7012334212','87010956612', '8012544413', '7777777', '8888888']})

print df

           Phone
0   +77013655566
1    87014324366
2     7014324366
3          11111
4         999999
5       43434343
6     8020556612
7   +77015452313
8     7012334212
9    87010956612
10    8012544413
11       7777777
12       8888888

if len(df.loc[df['Phone'].map(str).str.find('8') == 0]) == 11:
    df['Phone'].map(str).str.replace('8', '7', n = 1)
else: 
    #I will write other code



#Expected result:
      Phone
0   +77013655566
1    77014324366
2     7014324366
3          11111
4         999999
5       43434343
6     8020556612
7   +77015452313
8     7012334212
9    77010956612
10    8012544413
11       7777777
12       8888888

Answer 1

You can solve it as so

replacer = lambda x: x.replace('8', '7', 1) if x.startswith('8') and len(x) == 11 else x
df['Phone'] = df['Phone'].apply(replacer)