fix(no_NO): compute Norwegian MOD11 check digit so iban() passes stdnum validation

dev-requirements.txt

@@ -10,6 +10,7 @@ mypy-extensions>=1.0.0
 mypy>=1.15.0,<2
 packaging>=25.0
 pytest>=6.0.1
+python-stdnum>=1.20
 setuptools>=80.9.0
 tox>=4.24.1
 twine>=6.2.0

faker/providers/bank/no_NO/__init__.py

@@ -1,8 +1,21 @@
 from .. import Provider as BankProvider
 
+#: Weights applied to the first ten BBAN digits to derive the MOD11 check digit.
+MOD11_WEIGHTS = (6, 7, 8, 9, 4, 5, 6, 7, 8, 9)
+
 
 class Provider(BankProvider):
     """Implement bank provider for ``no_NO`` locale."""
 
     bban_format = "###########"
     country_code = "NO"
+
+    def bban(self) -> str:
+        """Generate a valid BBAN with correct MOD11 check digit."""
+        while True:
+            first_10 = self.numerify("##########")
+            check = sum(w * int(d) for w, d in zip(MOD11_WEIGHTS, first_10)) % 11
+            # A remainder of 10 has no single-digit representation, so that
+            # draw is discarded and another one taken.
+            if check != 10:
+                return first_10 + str(check)

tests/providers/test_bank.py

@@ -2,6 +2,8 @@
 
 import pytest
 
+from stdnum import iban as iban_validator
+
 from faker.providers.bank import Provider as BankProvider
 from faker.providers.bank.az_AZ import Provider as AzAzBankProvider
 from faker.providers.bank.cs_CZ import Provider as CsCZBankProvider
@@ -409,6 +411,10 @@ def test_iban(self, faker, num_samples):
             assert iban[:2] == NoNoBankProvider.country_code
             assert re.fullmatch(r"\d{2}\d{11}", iban[2:])
 
+    def test_iban_stdnum(self, faker, num_samples):
+        for _ in range(num_samples):
+            iban_validator.validate(faker.iban())
+
 
 class TestPlPl:
     """Test pl_PL bank provider"""

tox.ini

@@ -7,6 +7,7 @@ deps =
     coverage>=5.2
     freezegun
     pytest>=6.0.1
+    python-stdnum>=1.20
     ukpostcodeparser>=1.1.1
     validators>=0.13.0
     sphinx>=2.4,<3.0