From 60641c7f5564250c0596a8c6e2f97839fc6d32f1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Denis=20Krienb=C3=BChl?= <denis@href.ch>
Date: Mon, 13 Oct 2014 16:15:03 +0200
Subject: [PATCH] Adds the Swiss social security number.

Also known as "Sozialversicherungsnummer" / "Neue AHV Nummer".
---
 stdnum/ch/__init__.py | 21 +++++++++++++
 stdnum/ch/ssn.py      | 72 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 93 insertions(+)
 create mode 100644 stdnum/ch/__init__.py
 create mode 100644 stdnum/ch/ssn.py

diff --git a/stdnum/ch/__init__.py b/stdnum/ch/__init__.py
new file mode 100644
index 00000000..cea35648
--- /dev/null
+++ b/stdnum/ch/__init__.py
@@ -0,0 +1,21 @@
+# __init__.py - collection of Swiss numbers
+# coding: utf-8
+#
+# Copyright (C) 2014 Denis Krienbuehl
+#
+# 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
+
+"""Collection of Swiss numbers."""
diff --git a/stdnum/ch/ssn.py b/stdnum/ch/ssn.py
new file mode 100644
index 00000000..548ffa1a
--- /dev/null
+++ b/stdnum/ch/ssn.py
@@ -0,0 +1,72 @@
+# vat.py - functions for handling Swiss social security numbers
+#
+# Copyright (C) 2014 Denis Krienbuehl
+#
+# 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
+
+"""Swiss social security number ("Sozialversicherungsnummer").
+
+Also known as "Neue AHV Nummer".
+
+The Swiss Sozialversicherungsnummer is used to identify indivduals for taxation
+and pension purposes.
+
+The number is validated using EAN-13, though dashes are substitued for dots.
+
+>>> compact('756.9217.0769.85')
+'7569217076985'
+>>> format('7569217076985')
+'756.9217.0769.85'
+>>> validate('7569217076985')
+'7569217076985'
+>>> validate('756.9217.0769.85')
+'7569217076985'
+>>> validate('756.9217.0769.84')
+Traceback (most recent call last):
+    ...
+InvalidChecksum: ...
+"""
+
+from stdnum.exceptions import ValidationError
+from stdnum import ean
+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."""
+    return clean(number, ' .').strip()
+
+
+def format(number):
+    """Reformat the passed number to the standard format."""
+    number = compact(number)
+    return '.'.join((number[:3], number[3:7], number[7:11], number[11:]))
+
+
+def validate(number):
+    """Checks to see if the number provided is a valid
+    Swiss Sozialversicherungsnummer."""
+    return ean.validate(compact(number))
+
+
+def is_valid(number):
+    """Checks to see if the number provided is a valid
+    Sozialversicherungsnummer."""
+    try:
+        return bool(validate(number))
+    except ValidationError:
+        return False