What is a decorator in Python?

Key Takeaways

So, what we see here with the timer function is a decorator. Notice that what it actually does is return another function. What we do is we write the at symbol, then the name of the function, in this case it's timer, and we decorate a function with it. We put it on top of this function. So, rather than using the decorator syntax here, which is the at symbol, what we can actually do is write the following line. We can say the example function is equal to the timer function, and then we can pass the example function to it. When we do this, this is effectively the exact same as simply writing the decorator above the function. I know, seems a little bit strange, but that's all it's doing. It's simply taking this function right here, passing it to this decorator, and then replacing the function definition with whatever is returned from the decorator. So, as you can see, what the decorator really does is modify a function and typically add some behavior around it.