first commit

modules/account_be/ogm_vcs.py

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+# This file is part of Tryton.  The COPYRIGHT file at the top level of
+# this repository contains the full copyright notices and license terms.
+
+from stdnum.exceptions import (
+    InvalidChecksum, InvalidFormat, InvalidLength, ValidationError)
+from stdnum.util import clean, isdigits
+
+
+def compact(number: str) -> str:
+    """Convert the number to the minimal representation. This strips the number
+    of any invalid separators and removes surrounding whitespace."""
+    return clean(number, ' +/').strip()
+
+
+def calc_check_digits(number: str) -> str:
+    """Calculate the check digit that should be added."""
+    number = compact(number)
+    return '%02d' % ((int(number[:10]) % 97) or 97)
+
+
+def validate(number: str) -> str:
+    """Check if the number is a valid OGM-VCS."""
+    number = compact(number)
+    if not isdigits(number) or int(number) <= 0:
+        raise InvalidFormat()
+    if len(number) != 12:
+        raise InvalidLength()
+    if calc_check_digits(number) != number[-2:]:
+        raise InvalidChecksum()
+    return number
+
+
+def is_valid(number: str) -> bool:
+    """Check if the number is a valid VAT number."""
+    try:
+        return bool(validate(number))
+    except ValidationError:
+        return False
+
+
+def format(number: str) -> str:
+    """Format the number provided for output."""
+    number = compact(number)
+    number = number.rjust(12, '0')
+    return f'{number[:3]}/{number[3:7]}/{number[7:]}'