def _maybe_strip_i18n_prefix_and_normalize(number, possible_idd_prefix):
    """Strips any international prefix (such as +, 00, 011) present in the
    number provided, normalizes the resulting number, and indicates if an
    international prefix was present.

    Arguments:
    number -- The non-normalized telephone number that we wish to strip any international
              dialing prefix from.
    possible_idd_prefix -- The international direct dialing prefix from the region we
              think this number may be dialed in.

    Returns a 2-tuple containing:
      - The corresponding CountryCodeSource if an international dialing prefix
        could be removed from the number, otherwise
        CountryCodeSource.FROM_DEFAULT_COUNTRY if the number did not seem to
        be in international format.
      - The number with the prefix stripped.
    """
    if len(number) is 0:
        return (CountryCodeSource.FROM_DEFAULT_COUNTRY, number)
    # Check to see if the number begins with one or more plus signs.
    m = _PLUS_CHARS_PATTERN.match(number)
    if m:
        number = number[m.end():]
        # Can now normalize the rest of the number since we've consumed the
        # "+" sign at the start.
        return (CountryCodeSource.FROM_NUMBER_WITH_PLUS_SIGN,
                _normalize(number))

    # Attempt to parse the first digits as an international prefix.
    idd_pattern = re.compile(possible_idd_prefix)
    number = _normalize(number)
    stripped, number = _parse_prefix_as_idd(idd_pattern, number)
    if stripped:
        return (CountryCodeSource.FROM_NUMBER_WITH_IDD, number)
    else:
        return (CountryCodeSource.FROM_DEFAULT_COUNTRY, number)
dataset/ETHPy150Open daviddrysdale/python-phonenumbers/python/phonenumbers/phonenumberutil.py/_maybe_strip_i18n_prefix_and_normalize/operator `==` -> `is`