Regular Expression으로 전화번호 Search 구현하기

import re #다양한 종류의 전화번호를 파일에서 검색하기
with open('search.txt','rt',encoding='UTF8') as f: #한글이 포함된 파일에서 읽어들이기
    number = []
    for line in f:
        m = re.findall(r'[(]?(\d\d\d?)[)]?[-\s]?(\d\d\d\d?)-(\d\d\d\d)',line)
        if m:
            for i in m:
                number.append(("<TEL>"+i[0]+'-'+i[1]+'-'+i[2]+"<TEL>")) #형식을 <TEL><TEL>로 바꾸기
    print(number)
with open('number_list','w') as z:
    for k in number:
        z.write(k)
        z.write('\n')