input: Write a python function to generate a random password with a specific length and set of characters.
  assert len(generate_password(8)) == 8
  assert all(char in 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789*_/+-.,' for char in generate_password(12))
  assert len(generate_password(16)) == 16
output: import random
  
  def generate_password(length):
      characters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789*_/+-.,'
      password = ''.join(random.choice(characters) for _ in range(length))
      return password