add count_number_of_one_bits.py (#4195)

* count-bits

* update

bit_manipulation/count_number_of_one_bits.py

@@ -0,0 +1,34 @@
+def get_set_bits_count(number: int) -> int:
+    """
+    Count the number of set bits in a 32 bit integer
+    >>> get_set_bits_count(25)
+    3
+    >>> get_set_bits_count(37)
+    3
+    >>> get_set_bits_count(21)
+    3
+    >>> get_set_bits_count(58)
+    4
+    >>> get_set_bits_count(0)
+    0
+    >>> get_set_bits_count(256)
+    1
+    >>> get_set_bits_count(-1)
+    Traceback (most recent call last):
+        ...
+    ValueError: the value of input must be positive
+    """
+    if number < 0:
+        raise ValueError("the value of input must be positive")
+    result = 0
+    while number:
+        if number % 2 == 1:
+            result += 1
+        number = number >> 1
+    return result
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()