input: def generate_password():
      """Generate a random password that consists of 8 characters.
      The password should include uppercase and lowercase letters, and digits.
      Example:
      >>> generate_password()
      'A1b2C3d4'
      """
      pass
output:     import random
      import string
      
      characters = string.ascii_letters + string.digits
      password = ''.join(random.choice(characters) for _ in range(8))
      return password