Merge pull request #84 from itk-dev-rpa/feature/cpr-birth-date

Added get birth date function

Author: ghbm-itk

changelog.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- misc.cpr_util: Function to get birth date from cpr number.
+
 ## [2.7.1] - 2024-09-24
 
 ### Fixed

itk_dev_shared_components/misc/cpr_util.py

@@ -3,16 +3,15 @@
 from datetime import date
 
 
-def get_age(cpr: str, current_date: date = date.today()) -> int:
-    """Get the age of a person based on their cpr number
+def get_birth_date(cpr: str) -> date:
+    """Get the birth date of a person based on their cpr number
     using the 7th digit to infer the century.
 
     Args:
         cpr: The cpr number in the format 'ddmmyyxxxx'.
-        current_date: The date where the age is calculated from. Defaults to the current date.
 
     Returns:
-        The age in integer years based on the cpr number.
+        The birth date based on cpr number.
 
     Raises:
         ValueError: If the given cpr is not in 'ddmmyyxxxx' format.
@@ -51,7 +50,24 @@ def get_age(cpr: str, current_date: date = date.today()) -> int:
     else:
         year += t[2]
 
-    birthdate = date(year, month, day)
+    return date(year, month, day)
+
+
+def get_age(cpr: str, current_date: date = date.today()) -> int:
+    """Get the age of a person based on their cpr number
+    using the 7th digit to infer the century.
+
+    Args:
+        cpr: The cpr number in the format 'ddmmyyxxxx'.
+        current_date: The date where the age is calculated from. Defaults to the current date.
+
+    Returns:
+        The age in integer years based on the cpr number.
+
+    Raises:
+        ValueError: If the given cpr is not in 'ddmmyyxxxx' format.
+    """
+    birthdate = get_birth_date(cpr)
 
     age = current_date.year - birthdate.year - ((current_date.month, current_date.day) < (birthdate.month, birthdate.day))
 

tests/test_misc/test_cpr_util.py

@@ -43,6 +43,38 @@ def test_get_age_from_cpr(self):
         with self.assertRaises(ValueError):
             cpr_util.get_age("010190xxxx")
 
+    def test_get_birth_date_from_cpr(self):
+        """Test getting the age from a cpr number."""
+        # A table of fictional cpr-numbers and the expected birth dates.
+        test_data = (
+            ("0101920000", date(1992, 1, 1)),
+            ("0101921000", date(1992, 1, 1)),
+            ("0101922000", date(1992, 1, 1)),
+            ("0101923000", date(1992, 1, 1)),
+            ("0101154000", date(2015, 1, 1)),
+            ("0101924000", date(1992, 1, 1)),
+            ("0101155000", date(2015, 1, 1)),
+            ("0101925000", date(1892, 1, 1)),
+            ("0101156000", date(2015, 1, 1)),
+            ("0101926000", date(1892, 1, 1)),
+            ("0101157000", date(2015, 1, 1)),
+            ("0101927000", date(1892, 1, 1)),
+            ("0101158000", date(2015, 1, 1)),
+            ("0101928000", date(1892, 1, 1)),
+            ("0101159000", date(2015, 1, 1)),
+            ("0101929000", date(1992, 1, 1)),
+        )
+
+        for cpr, birth_date in test_data:
+            with self.subTest(cpr=cpr, birth_date=birth_date):
+                self.assertEqual(cpr_util.get_birth_date(cpr), birth_date)
+
+        with self.assertRaises(ValueError):
+            cpr_util.get_birth_date("010190-1234")
+
+        with self.assertRaises(ValueError):
+            cpr_util.get_birth_date("010190xxxx")
+
 
 if __name__ == '__main__':
     unittest.main()