input: from typing import List
  
  def generate_random_string(length: int) -> str:
      """ Generates a random string of a given length. The string will contain lowercase letters only.
      >>> generate_random_string(6)
      'abcxyz'
      >>> generate_random_string(4)
      'pqrs'
      """
      letters = string.ascii_lowercase
      return ''.join(random.choice(letters) for i in range(length))
output:     import random
      import string