input: def is_prime(num: int) -> bool:
      """ Determines if a given number is prime or not.
      >>> is_prime(17)
      True
      >>> is_prime(20)
      False
      """
      
      # Set initial value
      is_prime = True
      
      # Check for prime
      for i in range(2, num):
          if num % i == 0:
              is_prime = False
              break
      
      return is_prime
output:     if num <= 1:
          return False
      if num == 2:
          return True
      if num % 2 == 0:
          return False
      for i in range(3, int(num**0.5) + 1, 2):
          if num % i == 0:
              return False
      return True