Add support for Egypt TIN

Closes arthurdejong#225.

stdnum/eg/__init__.py

@@ -0,0 +1,24 @@
+# __init__.py - collection of Egypt 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
+
+"""Collection of Egypt numbers."""
+
+# provide aliases
+from stdnum.eg import tn as vat  # noqa: F401

stdnum/eg/tn.py

@@ -0,0 +1,110 @@
+# tn.py - functions for handling Egypt Tax Number 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
+
+"""Tax Registration Number (الرقم الضريبي, Egypt tax number).
+
+This number consists of 9 digits, usually separated into three groups
+using hyphens to make it easier to read, like XXX-XXX-XXX.
+
+More information:
+
+* https://emsp.mts.gov.eg:8181/EMDB-web/faces/authoritiesandcompanies/authority/website/SearchAuthority.xhtml?lang=en
+
+>>> validate('100-531-385')
+'100531385'
+>>> validate('٣٣١-١٠٥-٢٦٨')
+'331105268'
+>>> validate('12345')
+Traceback (most recent call last):
+    ...
+InvalidLength: ...
+>>> validate('VV3456789')
+Traceback (most recent call last):
+    ...
+InvalidFormat: ...
+>>> format('100531385')
+'100-531-385'
+"""  # noqa: E501
+
+from stdnum.exceptions import *
+from stdnum.util import clean, isdigits
+
+
+ARABIC_NUMBERS_MAP = {
+    # Arabic-indic digits. 
+    u'٠': '0',
+    u'١': '1',
+    u'٢': '2',
+    u'٣': '3',
+    u'٤': '4',
+    u'٥': '5',
+    u'٦': '6',
+    u'٧': '7',
+    u'٨': '8',
+    u'٩': '9',
+    # Extended arabic-indic digits.
+    u'۰': '0',
+    u'۱': '1',
+    u'۲': '2',
+    u'۳': '3',
+    u'۴': '4',
+    u'۵': '5',
+    u'۶': '6',
+    u'۷': '7',
+    u'۸': '8',
+    u'۹': '9',
+}
+
+
+def compact(number):
+    """Convert the number to the minimal representation.
+
+    This strips the number of any valid separators and removes surrounding
+    whitespace. It also converts arabic numbers.
+    """
+    number = clean(number, u' -–/').strip()
+    return ''.join([ARABIC_NUMBERS_MAP.get(c, c) for c in number])
+
+
+def validate(number):
+    """Check if the number is a valid Egypt Tax Number number.
+
+    This checks the length and formatting.
+    """
+    number = compact(number)
+    if len(number) != 9:
+        raise InvalidLength()
+    if not isdigits(number):
+        raise InvalidFormat()
+    return number
+
+
+def is_valid(number):
+    """Check if the number is a valid Egypt Tax Number number."""
+    try:
+        return bool(validate(number))
+    except ValidationError:
+        return False
+
+
+def format(number):
+    """Reformat the number to the standard presentation format."""
+    number = compact(number)
+    return '-'.join([number[:3], number[3:-3], number[-3:]])