98 lines
3 KiB
Python
98 lines
3 KiB
Python
# ssn.py - functions for handling SSNs
|
|
#
|
|
# Copyright (C) 2011, 2012, 2013 Arthur de Jong
|
|
#
|
|
# This library is free software; you can redistribute it and/or
|
|
# modify it under the terms of the GNU Lesser General Public
|
|
# License as published by the Free Software Foundation; either
|
|
# version 2.1 of the License, or (at your option) any later version.
|
|
#
|
|
# This library is distributed in the hope that it will be useful,
|
|
# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
# Lesser General Public License for more details.
|
|
#
|
|
# You should have received a copy of the GNU Lesser General Public
|
|
# License along with this library; if not, write to the Free Software
|
|
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
|
|
# 02110-1301 USA
|
|
|
|
"""SSN (U.S. Social Security Number).
|
|
|
|
The Social Security Number is used to identify individuals for taxation
|
|
purposes.
|
|
|
|
>>> validate('536-90-4399')
|
|
'536904399'
|
|
>>> validate('1112-23333') # dash in the wrong place
|
|
Traceback (most recent call last):
|
|
...
|
|
InvalidFormat: ...
|
|
>>> validate('666-00-0000') # invalid area
|
|
Traceback (most recent call last):
|
|
...
|
|
InvalidComponent: ...
|
|
>>> validate('078-05-1120') # blacklisted entry
|
|
Traceback (most recent call last):
|
|
...
|
|
InvalidComponent: ...
|
|
>>> compact('1234-56-789')
|
|
'123456789'
|
|
>>> format('111223333')
|
|
'111-22-3333'
|
|
"""
|
|
|
|
import re
|
|
|
|
from stdnum.exceptions import *
|
|
from stdnum.util import clean
|
|
|
|
|
|
# regular expression for matching SSN
|
|
_ssn_re = re.compile(
|
|
r'^(?P<area>[0-9]{3})-?(?P<group>[0-9]{2})-?(?P<serial>[0-9]{4})$')
|
|
|
|
# blacklist of SSNs
|
|
_ssn_blacklist = set(('078-05-1120', '457-55-5462', '219-09-9999'))
|
|
|
|
|
|
def compact(number):
|
|
"""Convert the number to the minimal representation. This strips the
|
|
number of any valid separators and removes surrounding whitespace."""
|
|
return clean(number, '-').strip()
|
|
|
|
|
|
def validate(number):
|
|
"""Checks to see if the number provided is a valid SSN. This checks
|
|
the length, groups and formatting if it is present."""
|
|
match = _ssn_re.search(clean(number, '').strip())
|
|
if not match:
|
|
raise InvalidFormat()
|
|
area = match.group('area')
|
|
group = match.group('group')
|
|
serial = match.group('serial')
|
|
# check for all-0 or some unused areas
|
|
# (9xx also won't be issued which includes the advertising range)
|
|
if area == '000' or area == '666' or area[0] == '9' or \
|
|
group == '00' or serial == '0000':
|
|
raise InvalidComponent()
|
|
# check blacklists
|
|
if format(number) in _ssn_blacklist:
|
|
raise InvalidComponent()
|
|
return compact(number)
|
|
|
|
|
|
def is_valid(number):
|
|
"""Checks to see if the number provided is a valid SSN. This checks
|
|
the length, groups and formatting if it is present."""
|
|
try:
|
|
return bool(validate(number))
|
|
except ValidationError:
|
|
return False
|
|
|
|
|
|
def format(number):
|
|
"""Reformat the passed number to the standard format."""
|
|
if len(number) == 9:
|
|
number = number[:3] + '-' + number[3:5] + '-' + number[5:]
|
|
return number
|