89 lines
2.9 KiB
Python
89 lines
2.9 KiB
Python
# rif.py - functions for handling Venezuelan VAT numbers
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# coding: utf-8
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#
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# Copyright (C) 2019 Arthur de Jong
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#
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# This library is free software; you can redistribute it and/or
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# modify it under the terms of the GNU Lesser General Public
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# License as published by the Free Software Foundation; either
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# version 2.1 of the License, or (at your option) any later version.
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#
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# This library is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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# Lesser General Public License for more details.
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#
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# You should have received a copy of the GNU Lesser General Public
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# License along with this library; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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# 02110-1301 USA
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"""RIF (Registro de Identificación Fiscal, Venezuelan VAT number).
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The Registro de Identificación Fiscal (RIF) is the Venezuelan fiscal
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registration number. The number consists of 10 digits where the first digit
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denotes the type of number (person, company or government) and the last digit
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is a check digit.
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>>> validate('V-11470283-4')
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'V114702834'
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>>> validate('V-11470283-3') # invalid check digit
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Traceback (most recent call last):
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...
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InvalidChecksum: ...
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"""
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from __future__ import annotations
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from stdnum.exceptions import *
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from stdnum.util import clean, isdigits
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def compact(number: str) -> str:
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"""Convert the number to the minimal representation. This strips the
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number of any valid separators and removes surrounding whitespace."""
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return clean(number, ' -').upper().strip()
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# Known number types and their corresponding value in the check
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# digit calculation
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_company_types = {
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'V': 4, # natural person born in Venezuela
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'E': 8, # foreign natural person
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'J': 12, # company
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'P': 16, # passport
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'G': 20, # government
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}
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def calc_check_digit(number: str) -> str:
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"""Calculate the check digit for the RIF."""
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number = compact(number)
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weights = (3, 2, 7, 6, 5, 4, 3, 2)
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c = _company_types[number[0]]
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c += sum(w * int(n) for w, n in zip(weights, number[1:9]))
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return '00987654321'[c % 11]
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def validate(number: str) -> str:
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"""Check if the number provided is a valid RIF. This checks the length,
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formatting and check digit."""
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number = compact(number)
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if len(number) != 10:
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raise InvalidLength()
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if number[0] not in _company_types:
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raise InvalidComponent()
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if not isdigits(number[1:]):
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raise InvalidFormat()
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if number[-1] != calc_check_digit(number):
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raise InvalidChecksum()
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return number
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def is_valid(number: str) -> bool:
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"""Check if the number provided is a valid RIF. This checks the length,
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formatting and check digit."""
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try:
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return bool(validate(number))
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except ValidationError:
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return False
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