如何从类方法中调用全局函数 [英] How to call global function from class method

问题描述

我有以下代码：

def __static_func(name):
    print 'Name = ' + name

class A:
    def __init__(self, name):
        self.name = name
    def fun(self):
        __static_func(self.name)

a = A('foo')
a.fun()

在Python 2.7上启动时，它会产生

When launched on Python 2.7, it produces

NameError: global name '_A__static_func' is not defined

所以问题是如何从类方法中调用全局函数？

So the question is how do I call global function from within class method?

推荐答案

我最近正在读一本书 O'Reilly学习Python （第944页，第31章），提到使用双下划线 __ 作为方法的起始字符或 Class 中的变量，它会自动将 _classname 附加到该函数e classname 是类名。这样做是为了将名称本地化为它所属的类。在伪私有类属性的上下文中，这称为名称处理。

I was recently reading a book "Learning Python by O'Reilly" (Page 944, Chapter 31) and it was mentioned that when you use double underscores __ as the starting characters of a method or a variable in the Class, it automatically appends the _classname to that function where classname is the class name. This is done to localize a name to the class to which it belongs. This is called Name Mangling in the context of Pseudoprivate class attributes.

这样，您可以在两个不同的类 A 中使用相同的名称 __ variable 和 B ，因为变量/方法将私有化为 _A__variable 和 _B__variable 。因此，只需用单个下划线为全局函数命名，以免发生这种冲突。

This way you can use the same name __variable in two different classes A and B as the variables/methods will become privately _A__variable and _B__variable respectively. So just name your global function something else with a single underscore for example to avoid this conflict.

这篇关于如何从类方法中调用全局函数的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！