Python Closures

Summary: in this tutorial, you’ll learn about Python closures and their practical applications.

Introduction to the Python closures #

In Python, you can define a function from the inside of another function. And this function is called a nested function. For example:

def say():
    greeting = 'Hello'

    def display():
        print(greeting)

    display()Code language: Python (python)

In this example, we define the display function inside the say function. The display function is called a nested function.

Inside the display function, you access the greeting variable from its nonlocal scope.

Python calls the greeting variable a free variable.

When you look at the display function, you actually look at:

• The display function itself.
• And the free variable greeting with the value 'Hello'.

So the combination of the display function and greeting variable is called a closure: