input: Write a function to generate a random password of length 8, which consists of alphanumeric characters and at least one special character. If the generated password does not contain at least one special character, it should be regenerated until it does.
  
  def generate_password():
      import string
      import random
      
      chars = string.ascii_letters + string.digits + string.punctuation
      pwd_length = 8
  
      password = ''
      for i in range(pwd_length):
          password += random.choice(chars)
      
      # Check if at least one special character exists in the password
      if any([char in string.punctuation for char in password]):
          return password
      else:
          return generate_password()
  
  assert len(generate_password()) == 8
  assert any([char in string.punctuation for char in generate_password()])
  assert all([char in (string.ascii_letters + string.digits + string.punctuation) for char in generate_password()])
output: def generate_password():
      import string
      import random
      
      chars = string.ascii_letters + string.digits + string.punctuation
      pwd_length = 8
  
      password = ''
      for i in range(pwd_length):
          password += random.choice(chars)
      
      # Check if at least one special character exists in the password
      if any([char in string.punctuation for char in password]):
          return password
      else:
          return generate_password()