python class decorator

ArticleDirectory 1. Origin 2. Make the code more elegant. 3. Make the code more elegant. 4. Add Parameters 5. Decorated functions with return values 6. apply multiple decorators 7. Flexible Use To understand Python's decorator, you must first know that the function is also an object in Python, so you can Copy a function to a variable Use a function as a parameter

, it provides us with a warm effect. Before talking about the decorator, you must first understand one thing. the functions in Python are not the same as those in Java and C ++, functions in Python can be passed to another function as parameters like common variables. for example: def foo(): print("foo")def bar(func): func()bar(foo) Officially return to our

Decorator and python decorator 1. What is a decoration device? The decorator is essentially a function. Its function is to decorate other functions and add additional functions to other functions. 2. Application scenarios If our program has been launched, we want to add new features for it. We originally wanted to modi

First, the adorner decorator The decorator design pattern allows you to dynamically wrap existing objects or functions so that you can modify existing responsibilities and behaviors, simply to dynamically extend existing functionality. In fact, the concept of AOP in other languages separates the real functions of objects or functions from other auxiliary functions. Second, the

;Now () - Execute Now: the2017-12-16Compared to the two-layer nested decorator, the 3-layer nesting effect is this:1 >>> now = log ('execute') (now)Third, Functools.wrapsThere is no problem with the definitions of the two decorator, but the last step is not the case. Because we're talking about functions and objects, and it has __name__ properties like that, but you see the functions after the

Python tutorial 11 -- Python decorator A function is also an object, and a function object can be assigned to a variable. Therefore, a function can also be called through a variable. The function object has a (Double underline + name + double underline) attribute. You can get the function name: Now, let's assume that we want to enhance the functions of the now (

Python's decorator is similar to java/c# 's annotation in its use, which is to decorate something for this method by adding a @xxx annotation to the method name. However, Java/c# 's annotation is also very daunting, too TMD complex, you want to play it, you need to know a bunch of annotation library documents, let people feel is learning another language. Python uses a very elegant method relative to

summary, the purpose of the decorator is to add additional functions to existing objects. 1.1. How does the demand come from? The definition of the decorator is very abstract. Let's look at a small example.Copy codeThe Code is as follows: def foo ():Print 'in foo ()'Foo ()This is a boring function. But suddenly there was a more boring person. We called him B Jun and said, "I want to see how long it took to

The Python decorator, closure, and functools tutorials are described in detail. Decorators) The decorator is a design pattern. If a class wants to add some functions of other classes without inheriting or directly modifying the source code, you can use the decorator pattern.

Python's adorner use is a very important part of the Python language, which is the embodiment of the decorative pattern in the programming pattern, and Python provides a special syntactic sugar that can be easily implemented in decorative mode.Series Articles A single-instance pattern of Python design patterns (i) Summary of common creation patterns of

, annotations are added to both Java and C. Of course, they also have some problems: sometimes you have to bypass many pitfalls to achieve your goals. These annotation features are also tied to some inherent features of these languages (like the "Directing" described by Martin Fowler ")A little different is that many C ++ programmers, including me, have realized the power of C ++ templates and are using this function like using macros.Many other languages also contain macro functions. although I

Python decorator if used well, it is the great God, use the best not to use ...The adorner (decorator) mainly contains two large properties:1, can not change the original function call mode2, can not change the original function of the codeThe first one says I don't need to change the structure of the original code.The second one says, I don't need to change the