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 as a string.
  assert generate_password()=="A1b2C3d4"
  assert generate_password()=="XyZ9w8q7"
  assert generate_password()=="5JkLmN6p"
  assert generate_password()=="R0sT1Uv2"
  assert len(generate_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))