input: from typing import List
  import string
  import random
  
  def generate_random_string(length: int) -> str:
      """ Generate a random string of length 8 containing alphanumeric characters.
      >>> generate_random_string(8)
      'a1b2c3d4'
      >>> generate_random_string(8)
      'Z9X8Y7W6'
      """
      chars = string.ascii_letters + string.digits
      return ''.join(random.choice(chars) for _ in range(length))
output:     chars = string.ascii_letters + string.digits
      return ''.join(random.choice(chars) for _ in range(length))