new_contents: 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()
  
subject: add count_number_of_one_bits.py (#4195)