declaring 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
!
'''

def functionName(variable):
  //function content

#Functions
def string():
  print('This is a function')
  
  print(string())

  def my_function():
  print("Hello from a function")


  my_function()