input: Write a python function to generate a random password.
  assert len(randomPassword()) == 8
  assert isinstance(randomPassword(), str)
  assert any(char.isdigit() for char in randomPassword())
  assert any(char.isalpha() for char in randomPassword())
output: import random
  import string
  
  def randomPassword():
      characters = string.ascii_letters + string.digits
      password = ''.join(random.choice(characters) for i in range(8))
      return password