input: Write a python function to generate a random password of length 8 including letters, digits, and punctuation.
  assert len(generate_password()) == 8
  assert any(c.islower() for c in generate_password())
  assert any(c.isupper() for c in generate_password())
  assert any(c.isdigit() for c in generate_password())
  assert any(c in string.punctuation for c in generate_password())
output: import random
  import string
  
  def generate_password():
      characters = string.ascii_letters + string.digits + string.punctuation
      password = ''.join(random.choice(characters) for i in range(8))
      if (any(c.islower() for c in password) and
          any(c.isupper() for c in password) and
          any(c.isdigit() for c in password) and
          any(c in string.punctuation for c in password)):
          return password
      else:
          return generate_password()