functions.py

from __future__ import print_function  # Ignore this

# Example 1 - Function with argument
def say_hello(name):
    # Prints 'Hello {name}!' to the screen
    print("Hello {}!".format(name))
  
# We 'invoke' / 'call' a function using the ()s
say_hello('Nick')

# If you want to assign the function to a variable, just don't do the ()s
a_variable = say_hello

# Then you can invoke it using ()s
a_variable('Matt')


# Example 2 - Function with no argument
def say_hello_to_stranger():
    # Prints 'Hello stranger!' to the screen
    print("Hello stranger!")
  
say_hello_to_stranger()
some_variable = say_hello_to_stranger
some_variable()