Add Spanish postcode validator

Closes #401

Author: Victor

stdnum/es/postal_code.py

@@ -0,0 +1,84 @@
+# postal_code.py - functions for handling Spanish postal code numbers
+# coding: utf-8
+#
+# Copyright (C) 2023 Víctor Ramos
+#
+# 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
+
+"""Postcode (the Spanish postal code).
+
+The Spanish postal code consists of five digits where the first two digits,
+ranging 01 to 52, correspond either to one of the 50 provinces of Spain or to
+one of the two autonomous cities on the African coast.
+
+More information:
+
+* https://en.wikipedia.org/wiki/Postal_codes_in_Spain
+
+>>> validate('01000')
+'01000'
+>>> validate('52000')
+'52000'
+>>> validate('00000')
+Traceback (most recent call last):
+    ...
+InvalidComponent: ...
+>>> validate('53000')
+Traceback (most recent call last):
+    ...
+InvalidComponent: ...
+>>> validate('99999')
+Traceback (most recent call last):
+    ...
+InvalidComponent: ...
+>>> validate('5200')
+Traceback (most recent call last):
+    ...
+InvalidLength: ...
+>>> validate('520000')
+Traceback (most recent call last):
+    ...
+InvalidLength: ...
+"""
+
+
+from stdnum.exceptions import *
+from stdnum.util import clean, isdigits
+
+
+def compact(number):
+    """Convert the number to the minimal representation."""
+    return clean(number, ' ').strip()
+
+
+def validate(number):
+    """Check if the number provided is a valid postal code."""
+    number = compact(number)
+    if len(number) != 5:
+        raise InvalidLength()
+    if not isdigits(number):
+        raise InvalidFormat()
+    if not '01' <= number[:2] <= '52':
+        raise InvalidComponent()
+    return number
+
+
+def is_valid(number):
+    """Check if the number provided is a valid postal code."""
+    try:
+        return bool(validate(number))
+    except ValidationError:
+        return False