How to create and use closures in Python?

A closure refers to defining another function within a function, where the inner function can access variables from the outer function. In Python, it is very simple to create and use closures by following these steps:

1. Define an inner function within an outer function.
2. Inner functions have access to the variables of outer functions.
3. The outer function returns the inner function.

Here is a simple example of a closure:

def outer_func(x):
    def inner_func(y):
        return x + y
    return inner_func

closure = outer_func(5)
result = closure(3) # result = 8

In this example, outer_func is the outer function and inner_func is the inner function. outer_func takes a parameter x and returns the inner function inner_func. The inner function inner_func takes a parameter y and returns the result of x + y.

When we call outer_func(5), we obtain a closure that contains the value of the variable x from the outer function as 5. Then when we call closure(3), we are essentially calling the inner function inner_func, which accesses the variable x from the outer function and ultimately returns 8.

Using closures, we can easily encapsulate specific logic and reuse it in different places to improve the reusability and readability of the code.