functions.py

def hello_world():  # function named my_function
    print("Hello, World!")

for i in range(5):
    hello_world()   # call function defined above 5 times

print('I want to be a function')
print('I want to be a function')
print('I want to be a function')

def fun():  # Define a function to replace duplicate lines in the file.
    print('I want to be a function')

for i in range(3):
    fun()

산출물 (Output)

Hello, World!
Hello, World!
Hello, World!
Hello, World!
Hello, World!
I want to be a function
I want to be a function
I want to be a function
I want to be a function
I want to be a function
I want to be a function

* Functions are a convenient way to divide your code into useful blocks, make it more readable and help reuse it.
Functions are defined using the keyword "def", followed by the function's name.