# stdnum.in_.aadhaar

Aadhaar (Indian personal identity number).

Aadhaar is a 12 digit identification number that can be obtained by Indian citizens, non-residents passport holders of India and resident foreign nationals. The number is issued by the Unique Identification Authority of India (UIDAI).

Aadhaar is made up of 12 digits where the last digits is a check digit calculated using the Verhoeff algorithm. The numbers are generated in a random, non-repeating sequence and do not begin with 0 or 1.

More information:

- https://en.wikipedia.org/wiki/Aadhaar

- https://web.archive.org/web/20140611025606/http://uidai.gov.in/UID_PDF/Working_Papers/A_UID_Numbering_Scheme.pdf

    >>> validate('234123412346')
    '234123412346'
    >>> validate('234123412347')
    Traceback (most recent call last):
        ...
    InvalidChecksum: ...
    >>> validate('123412341234')  # number should not start with 0 or 1
    Traceback (most recent call last):
        ...
    InvalidFormat: ...
    >>> validate('643343121')
    Traceback (most recent call last):
        ...
    InvalidLength: ...
    >>> validate('222222222222')  # number cannot be a palindrome
    Traceback (most recent call last):
        ...
    InvalidFormat: ...
    >>> format('234123412346')
    '2341 2341 2346'
    >>> mask('234123412346')
    'XXXX XXXX 2346'

stdnum.in_.aadhaar.aadhaar_re = re.compile('^[2-9][0-9]{11}$')

  Regular expression used to check syntax of Aadhaar numbers.

stdnum.in_.aadhaar.compact(number: str) → str

  Convert the number to the minimal representation. This strips the number of any valid separators and removes surrounding whitespace.

stdnum.in_.aadhaar.format(number: str) → str

  Reformat the number to the standard presentation format.

stdnum.in_.aadhaar.is_valid(number: str) → bool

  Check if the number provided is a valid Aadhaar number. This checks the length, formatting and check digit.

stdnum.in_.aadhaar.mask(number: str) → str

  Masks the first 8 digits as per Ministry of Electronics and Information Technology (MeitY) guidelines.

stdnum.in_.aadhaar.validate(number: str) → str

  Check if the number provided is a valid Aadhaar number. This checks the length, formatting and check digit.