Change format number from 0888888888 to 0888-88-88-88 in text using python

#-*- coding:utf-8 -*-
import re, fileinput
File = "bbb.txt"
for line in fileinput.FileInput(File, inplace=1):
    pattern = re.compile(r'\d{10}')
    if re.search(pattern,line):
        line = re.sub(r'(\d{4})(\d{2})(\d{2})(\d{2})',r'\1-\2-\3-\4',line).strip()
        print line.strip()
    else:
         print line.strip()