Add support for Montenegro TIN

stdnum/me/__init__.py

@@ -19,3 +19,6 @@
 # 02110-1301 USA
 
 """Collection of Montenegro numbers."""
+
+# provide aliases
+from stdnum.me import pib as vat  # noqa: F401

stdnum/me/pib.py

@@ -0,0 +1,80 @@
+# pib.py - functions for handling Montenegro PIB numbers
+# coding: utf-8
+#
+# Copyright (C) 2022 Leandro Regueiro
+#
+# 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
+
+"""PIB (Poreski Identifikacioni Broj, Montenegro tax number).
+
+This number consists of 8 digits.
+
+More information:
+
+* http://www.pretraga.crps.me:8083/
+* https://www.vatify.eu/montenegro-vat-number.html
+
+>>> validate('02655284')
+'02655284'
+>>> validate('12345')
+Traceback (most recent call last):
+    ...
+InvalidLength: ...
+>>> validate('12345XYZ')
+Traceback (most recent call last):
+    ...
+InvalidFormat: ...
+>>> format('02655284')
+'02655284'
+"""
+
+from stdnum.exceptions import *
+from stdnum.util import clean, isdigits
+
+
+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, ' ')
+
+
+def validate(number):
+    """Check if the number is a valid Montenegro PIB number.
+
+    This checks the length and formatting.
+    """
+    number = compact(number)
+    if len(number) != 8:
+        raise InvalidLength()
+    if not isdigits(number):
+        raise InvalidFormat()
+    return number
+
+
+def is_valid(number):
+    """Check if the number is a valid Montenegro PIB number."""
+    try:
+        return bool(validate(number))
+    except ValidationError:
+        return False
+
+
+def format(number):
+    """Reformat the number to the standard presentation format."""
+    return compact(number)