input: Write a function to generate a random password consisting of 8 characters. The password should include a mix of uppercase and lowercase letters, as well as digits. Return the generated password.
  assert generate_password() is not None
  password = generate_password()
  assert len(password) == 8
output: import random
  import string
  
  def generate_password():
      characters = string.ascii_letters + string.digits
      return ''.join(random.choice(characters) for _ in range(8))