How to run def code in python code example

Example: how to make a function in python

def test_function(argument1,argument2,argument3) :
  # Do something with the code, and the arguments.
  print(argument1)
  print(argument2)
  print(argument3)
  
# Calling the function.

test_function('Hello','World','!')

# Output
'''
Hello
World
!
'''