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Exploring Python Closures: Examples and Use Cases (Summary)

Stephen Gruppetta
Exploring Python Closures: Examples and Use Cases Stephen Gruppetta 01:55
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Now you know that a closure is a function object typically defined inside another function in Python. Closures grab the objects defined in their enclosing scope and combine them with the inner function object to create a callable object with an extended scope.

You can use closures in multiple scenarios, especially when you need to retain the state between consecutive function calls or write a decorator. So, knowing how to use closures can be an excellent skill for a Python developer.

In this video course, you’ve learned:

  • What closures are and how they work in Python
  • When closures can be used in practice
  • How callable instances can replace closures

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00:00 It’s time to bring some closure to this course on Python closures. And let’s do so by looking at some of the key topics you’ve learned about in this course.

00:08 Closures are inner functions that retain access to objects defined within the enclosing scope. Here’s what this looks like. You define an outer function.

00:18 Within it, you define a variable, such as the list captured_variable in this case. It doesn’t have to be a list. This could be any data type.

00:26 Also, with an outer function, you define an inner function, and as long as that inner function has a reference to the variable created in the enclosing scope, so that’s captured_variable in this case, then that creates a closure.

00:40 So the inner function will always maintain a reference to the captured_variable, even when the scope of the outer function no longer exists.

00:52 You can think of a closure as an enclosure surrounding the function that captures objects that are defined outside this function.

01:01 Closures enable functions to maintain state, allowing function calls to communicate with previous and future calls of the same function. And in this course, you explored some use cases of closures.

01:13 These included factory functions, stateful functions, and decorators. But there are other uses of closures such as memoization and function callbacks. And if you want to find out about these and to read more about closures, then you can have a look at the accompanying tutorial, Python Closures: Common Use Cases and Examples.

01:33 And if you want to read more about one of the main use cases of closures, decorators, then there’s a tutorial and a video course here on Real Python for you.

01:43 I hope you enjoyed this course on closures. I hope you learned a lot from it. Now it’s time to open your favorite code editor and start exploring closures.

01:53 Good luck.

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