Fixed #15 - implement Iran national id number (#222)

Author: microdataxyz

idnumbers/nationalid/IRN.py

@@ -0,0 +1,43 @@
+import re
+from types import SimpleNamespace
+from typing import Optional
+from .util import CHECK_DIGIT, validate_regexp, weighted_modulus_digit, letter_to_number
+
+
+def normalize(id_number: str) -> str:
+    """strip out useless characters/whitespaces"""
+    return id_number.replace('-', '')
+
+
+class NationalID:
+    """
+    Iran national id number, (کارت ملی/kart-e-meli)
+    https://en.wikipedia.org/wiki/National_identification_number#Iran,_Islamic_Republic_of
+    """
+    METADATA = SimpleNamespace(**{
+        'iso3166_alpha2': 'IR',
+        'min_length': 10,
+        'max_length': 10,
+        'parsable': False,
+        'checksum': True,
+        'regexp': re.compile(r'^\d{3}-?\d{6}-?\d$')
+    })
+
+    MULTIPLIER = [10, 9, 8, 7, 6, 5, 4, 3, 2]
+
+    @staticmethod
+    def validate(id_number: str) -> bool:
+        """
+        Validate
+        """
+        if not validate_regexp(id_number, NationalID.METADATA.regexp):
+            return False
+        return NationalID.checksum(id_number) == int(id_number[-1])
+
+    @staticmethod
+    def checksum(id_number: str) -> Optional[CHECK_DIGIT]:
+        """algorithm: https://github.com/mohammadv184/idvalidator/blob/main/validate/nationalid/nationalid.go"""
+        normalized = normalize(id_number)
+        numbers = [int(i) for i in normalized]
+        modulus = weighted_modulus_digit(numbers[:-1], NationalID.MULTIPLIER, 11, True)
+        return modulus if modulus < 2 else 11 - modulus

tests/nationalid/test_IRN.py

@@ -0,0 +1,16 @@
+from unittest import TestCase
+from idnumbers.nationalid import IRN
+
+
+class TestIRNValidation(TestCase):
+    def test_normal_case(self):
+        self.assertTrue(IRN.NationalID.validate('472-171992-2'))
+        self.assertTrue(IRN.NationalID.validate('4608968882'))
+        self.assertTrue(IRN.NationalID.validate('1111111111'))
+        self.assertTrue(IRN.NationalID.validate('0939092001'))
+
+    def test_error_case(self):
+        self.assertFalse(IRN.NationalID.validate('472-171992-1'))
+        self.assertFalse(IRN.NationalID.validate('2130396217'))
+        self.assertFalse(IRN.NationalID.validate('0000000001'))
+        self.assertFalse(IRN.NationalID.validate('abcd1234'))