from re import compile
VALID_PHONE_PATTERNS = [
"^(\d{10})$",
"^(\d{3})\-(\d{3})\-(\d{4})$",
"^(\d{3})\.(\d{3})\.(\d{4})$",
"^\((\d{3})\)\s?(\d{3})\-(\d{4})$",
"^(\d{3})\-(\d{4})$"]
def validate_phone_number(phn):
for pattern in VALID_PHONE_PATTERNS:
res = compile(pattern).findall(phn)
if res:
return "".join(res[0])
return None