input: Write a function to create a Python script that adds two numbers together and prints the result. The function should take two parameters, add them, and print the sum.
  def add(a, b):
      sum = a + b
      print(sum)
  
  assert add(5, 7)==None
  assert add(3, 4)==None
  assert add(0, 0)==None
  assert add(-1, 1)==None
  assert add(-5, -3)==None
output: def add(a, b):
      sum = a + b
      print(sum)