From ebbd1af2b947af5293ffb1b2078222ef4475b17d Mon Sep 17 00:00:00 2001
From: Arthur de Jong <arthur@arthurdejong.org>
Date: Sat, 18 Feb 2012 14:16:27 +0000
Subject: add a NIP (Numer Identyfikacji Podatkowej, Polish VAT number) module

git-svn-id: http://arthurdejong.org/svn/python-stdnum/python-stdnum@140 9dea7c4f-944c-4273-ac1a-574ede026edc
---
 stdnum/pl/__init__.py |  0
 stdnum/pl/nip.py      | 67 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 67 insertions(+)
 create mode 100644 stdnum/pl/__init__.py
 create mode 100644 stdnum/pl/nip.py

(limited to 'stdnum/pl')

diff --git a/stdnum/pl/__init__.py b/stdnum/pl/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/stdnum/pl/nip.py b/stdnum/pl/nip.py
new file mode 100644
index 0000000..64dadf1
--- /dev/null
+++ b/stdnum/pl/nip.py
@@ -0,0 +1,67 @@
+# nip.py - functions for handling Polish VAT numbers
+#
+# Copyright (C) 2012 Arthur de Jong
+#
+# 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
+
+"""Module for handling Polish NIP (Numer Identyfikacji Podatkowej, VAT)
+numbers.
+
+The number consists of 10 digit with a straightforward weighted checksum.
+
+>>> compact('PL 8567346215')
+'8567346215'
+>>> is_valid('PL 8567346215')
+True
+>>> is_valid('PL 8567346216')  # invalid check digits
+False
+>>> format('PL 8567346215')
+'856-734-62-15'
+"""
+
+from stdnum.util import clean
+
+
+def compact(number):
+    """Convert the number to the minimal representation. This strips the
+    number of any valid separators and removes surrounding whitespace."""
+    number = clean(number, ' -').upper().strip()
+    if number.startswith('PL'):
+        number = number[2:]
+    return number
+
+
+def checksum(number):
+    """Calculate the checksum."""
+    weights = (6, 5, 7, 2, 3, 4, 5, 6, 7, -1)
+    return sum(weights[i] * int(n) for i, n in enumerate(number)) % 11
+
+
+def is_valid(number):
+    """Checks to see if the number provided is a valid VAT number. This
+    checks the length, formatting and check digit."""
+    try:
+        number = compact(number)
+    except:
+        return False
+    return number.isdigit() and len(number) == 10 and \
+           checksum(number) == 0
+
+
+def format(number):
+    """Reformat the passed number to the standard format."""
+    number = compact(number)
+    return '-'.join((number[0:3], number[3:6], number[6:8], number[8:]))
-- 
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