input: Write a python function to generate a random password of a given length using a combination of lowercase, uppercase, digits, and punctuation characters.
  assert len(get_password(8))==8
  assert len(get_password(12))==12
  assert all(c in string.ascii_letters + string.digits + string.punctuation for c in get_password(10))
output: import random
  import string
  
  def get_password(length):
      if length < 1:
          return ""
      
      all_chars = string.ascii_letters + string.digits + string.punctuation
      password = ''.join(random.choice(all_chars) for _ in range(length))
      
      return password