Master

bit_manipulation/README.md

@@ -9,3 +9,22 @@ Bit manipulation is the act of manipulating bits to detect errors (hamming code)
 * <https://wiki.python.org/moin/BitManipulation>
 * <https://wiki.python.org/moin/BitwiseOperators>
 * <https://www.tutorialspoint.com/python3/bitwise_operators_example.htm>
+
+## Example
+
+Below is a simple example using the `get_set_bits_count_using_brian_kernighans_algorithm`
+function from [bit_manipulation/count_number_of_one_bits.py](bit_manipulation/count_number_of_one_bits.py).
+
+```python
+from bit_manipulation.count_number_of_one_bits import get_set_bits_count_using_brian_kernighans_algorithm
+
+print(get_set_bits_count_using_brian_kernighans_algorithm(25))  # 3
+print(get_set_bits_count_using_brian_kernighans_algorithm(58))  # 4
+```
+
+This repository also includes doctest examples in the implementation that can be run with:
+
+```bash
+python3 bit_manipulation/count_number_of_one_bits.py
+```
+

tests/test_count_number_of_one_bits.py

@@ -0,0 +1,22 @@
+import unittest
+
+from bit_manipulation.count_number_of_one_bits import (
+    get_set_bits_count_using_brian_kernighans_algorithm,
+    get_set_bits_count_using_modulo_operator,
+)
+
+
+class TestCountSetBits(unittest.TestCase):
+    def test_examples(self):
+        self.assertEqual(get_set_bits_count_using_brian_kernighans_algorithm(25), 3)
+        self.assertEqual(get_set_bits_count_using_brian_kernighans_algorithm(58), 4)
+        self.assertEqual(get_set_bits_count_using_modulo_operator(37), 3)
+        self.assertEqual(get_set_bits_count_using_modulo_operator(0), 0)
+
+    def test_negative_input_raises(self):
+        with self.assertRaises(ValueError):
+            get_set_bits_count_using_brian_kernighans_algorithm(-1)
+
+
+if __name__ == "__main__":
+    unittest.main()