Shulou(Shulou.com)06/03 Report--

This article mainly explains the functions and features of python decorator. The content of the explanation is simple and clear, and it is easy to learn and understand. Please follow the editor's train of thought to study and learn the functions and features of python decorator.

Decorator summary

What is a decorator? Handle the function of the function, add a function, but does not affect the internal structure of the original function in the example of life: add a shell to the mobile phone, the shell protects the phone

What's the use of the decorator? Enhance the function of function

The decorator uses the scene to increase the behavior code reuse of the decorated function.

One function takes another function as an argument, which is called a higher-order function.

Important characteristics of function

1. In python, everything is an object, so a function is also an object, so a function can be assigned to a variable.

Define an add function whose function is to add two numbers

The system assigns a memory address to the function: 0x00000000021B3798

two。 One function can be used as the return value of another function

3. One function can be nested in another function.

4. One function can be used as an argument to another function.

Let's take a look at the map function.

The map function maps the specified sequence according to the specified function, which can effectively improve the running efficiency of the program.

Take a look at the source code of the map function: map (func, * iterables)

The map function takes two parameters:

Func: specify function function

Iterables: iterable object, one or more sequences, that is, the argument corresponding to the function

Decorator

To achieve a function, add the phrase "don't work hard when you are young" without changing the internal structure of the test function.

Figure out how the decorator works:

Write a higher-order function, that is, the argument is a function, and the return function is also a function; in the above example, the transfer function test is used as the argument, and finally the function test is returned.

In the use of syntax sugar @ to simplify assignment operations

But this code is flawed: the test function returns the function name directly, so it's not easy to call later.

Change into:

Thank you for your reading, the above is the content of "the functions and features of python decorator". After the study of this article, I believe you have a deeper understanding of the functions and characteristics of python decorator, and the specific use needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.