input: Write a python function to generate a random password of length 8 containing letters, digits, and punctuation.
  assert len(generatePassword())==8
  assert any(char.isdigit() for char in generatePassword())
  assert any(char.isalpha() for char in generatePassword())
  assert any(char in string.punctuation for char in generatePassword())
output: import random
  import string
  
  def generatePassword():
      characters = string.ascii_letters + string.digits + string.punctuation
      password = ''.join(random.choice(characters) for _ in range(8))
      return password