python静态方法

Python静态方法 (Python static method)

In this quick post, we will learn how to create and use a Python static method. We will also have a look at what advantages and disadvantages static methods offer as compared to the instance methods. Let’s get started.

在这篇快速文章中，我们将学习如何创建和使用Python静态方法。 我们还将看看静态方法与实例方法相比有哪些优点和缺点。 让我们开始吧。

什么是静态方法？ (What is a static method?)

Static methods in Python are extremely similar to python class level methods, the difference being that a static method is bound to a class rather than the objects for that class.

Python中的静态方法与python类级别的方法极为相似，不同之处在于静态方法绑定到一个类而不是该类的对象。

This means that a static method can be called without an object for that class. This also means that static methods cannot modify the state of an object as they are not bound to it. Let’s see how we can create static methods in Python.

这意味着可以在没有该类对象的情况下调用静态方法。 这也意味着静态方法无法修改对象的状态，因为它们没有绑定到对象。 让我们看看如何在Python中创建静态方法。

创建python静态方法 (Creating python static methods)

Python Static methods can be created in two ways. Let’s see each of the ways here:

Python静态方法可以通过两种方式创建。 让我们看看这里的每种方式：

使用staticmethod（） (Using staticmethod())

Let’s directly jump to sample code snippet on how to use the staticmethod() approach:

让我们直接跳转到如何使用staticmethod()方法的示例代码片段：

class Calculator:def addNumbers(x, y):return x + y# create addNumbers static method
Calculator.addNumbers = staticmethod(Calculator.addNumbers)print('Product:', Calculator.addNumbers(15, 110))

Note that we called the addNumbers we created without an object. When we run this program, here is the output we will get:

There were no surprises there. This approach is controlled as at each place, it is possible to create a static method out of a class method as well. Let’s see another approach with the same example here.

请注意，我们在没有对象的情况下调用了我们创建的addNumbers。 当我们运行该程序时，将获得以下输出：

那里没有惊喜。 这种方法在每个地方都受到控制，因此也可以从类方法中创建静态方法。 让我们在这里查看带有相同示例的另一种方法。

使用@staticmethod (Using @staticmethod)

This is a more subtle way of creating a Static method as we do not have to rely on a statement definition of a method being a class method and making it static at each place you make it static.

这是创建静态方法的一种更微妙的方法，因为我们不必依赖于方法的语句定义，该方法是类方法，并且在使它变为静态的每个位置都使其成为静态。

Let’s use this annotation in a code snippet:

让我们在代码片段中使用此注释：

class Calculator:# create addNumbers static method@staticmethoddef addNumbers(x, y):return x + yprint('Product:', Calculator.addNumbers(15, 110))

When we run this program, here is the output we will get:

This was actually a much better way to create a static method as the intention of keeping the method static is clear as soon as we create it and mark it with the @staticmethod annotation.

当我们运行该程序时，将获得以下输出：

实际上，这是创建静态方法的一种好得多的方法，因为在我们创建静态方法并使用@staticmethod批注对其进行标记后，就保持了静态方法的意图很明确。

Python静态方法的优点 (Advantages of Python static method)

Static methods have a very clear use-case. When we need some functionality not w.r.t an Object but w.r.t the complete class, we make a method static. This is pretty much advantageous when we need to create Utility methods as they aren’t tied to an object lifecycle usually.

静态方法有一个非常明确的用例。 当我们需要某些功能而不是对象，而需要完整的类时，我们可以使方法静态化。 当我们需要创建Utility方法时，这是非常有利的，因为它们通常与对象生命周期无关。

Finally, note that in a static method, we don’t need the self to be passed as the first argument.

最后，请注意，在静态方法中，我们不需要将self作为第一个参数传递。

API Reference: Python Documentation

API参考： Python文档

翻译自: https://www.journaldev.com/18722/python-static-method

python静态方法