http://programmingpraxis.com/2011/12/13/validating-telephone

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:
        myre = compile(pattern)
        if myre.match(phn):
            return True
    return False