import re def normalize(number): pattern = re.compile(r'\+?1?.?.?([2-9]\d{2}).?.?(\d{3}).?([2-9][0-8]\d{2}$)') tmp = pattern.match(number) if(tmp): return '1' + '-' + tmp.group(1) + '-' + tmp.group(2) + '-' + tmp.group(3) else: raise ValueError('Ungültige Telefonnummer') bruh = normalize("1-989-111-2222") print(bruh)