# stdnum.fi.ytunnus

Y-tunnus (Finnish business identifier).

The number is an 8-digit code with a weighted checksum.

    >>> validate('2077474-0')
    '20774740'
    >>> validate('2077474-1')  # invalid check digit
    Traceback (most recent call last):
        ...
    InvalidChecksum: ...
    >>> format('2077474-0')
    '2077474-0'

stdnum.fi.ytunnus.compact(number)

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

stdnum.fi.ytunnus.format(number)

  Reformat the number to the standard presentation format.

stdnum.fi.ytunnus.is_valid(number)

  Check if the number is a valid business identifier.

stdnum.fi.ytunnus.validate(number)

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