def is_alpha_number(number):
 if (not _is_viable_phone_number(number)):
  return False
 (extension, stripped_number) = _maybe_strip_extension(number)
 return bool(fullmatch(_VALID_ALPHA_PHONE_PATTERN, stripped_number))

def is_alpha_number ( number ) : if ( not _is_viable_phone_number ( number ) ) : return False ( extension , stripped_number ) = _maybe_strip_extension ( number ) return bool ( fullmatch ( _VALID_ALPHA_PHONE_PATTERN , stripped_number ) )
checks if the number is a valid vanity number such as 800 microsoft .