根据http://www.faqs.org/docs/diveintopython/fileinfo_private.html:

像大多数语言一样,Python具有 私有元素的概念: 私人 函数,这些函数不能被调用 在模块外

然而,如果我定义两个文件:

#a.py
__num=1

and:

#b.py
import a
print a.__num

当我运行b.py时,它输出1而不给出任何异常。是diveintopython错了,还是我误解了什么?是否有方法将模块的函数定义为私有?


当前回答

嵌入闭包或函数是一种方法。这在JS中很常见,但对于非浏览器平台或浏览器worker来说不是必需的。

在Python中,这似乎有点奇怪,但如果确实需要隐藏一些东西,那可能是一种方法。更重要的是,使用python API并将需要隐藏在C(或其他语言)中的内容可能是最好的方法。如果做不到这一点,我会把代码放在一个函数中,调用它,让它返回你想要导出的项。

其他回答

你可以添加一个内部函数:

def public(self, args):
   def private(self.root, data):
       if (self.root != None):
          pass #do something with data

如果你真的需要那种程度的隐私的话。

这是一个古老的问题,但是模块私有(一个下划线)和类私有(两个下划线)被破坏的变量现在都包含在标准文档中:

Python教程»类»私有变量

见PEP8指南:

方法名称和实例变量

Use the function naming rules: lowercase with words separated by underscores as necessary to improve readability. Use one leading underscore only for non-public methods and instance variables. To avoid name clashes with subclasses, use two leading underscores to invoke Python’s name mangling rules. Python mangles these names with the class name: if class Foo has an attribute named __a, it cannot be accessed by Foo.__a. (An insistent user could still gain access by calling Foo._Foo__a.) Generally, double leading underscores should be used only to avoid name conflicts with attributes in classes designed to be subclassed.

为传承而设计

Always decide whether a class’s methods and instance variables (collectively: “attributes”) should be public or non-public. If in doubt, choose non-public; it’s easier to make it public later than to make a public attribute non-public. Public attributes are those that you expect unrelated clients of your class to use, with your commitment to avoid backwards incompatible changes. Non-public attributes are those that are not intended to be used by third parties; you make no guarantees that non-public attributes won’t change or even be removed. We don’t use the term “private” here, since no attribute is really private in Python (without a generally unnecessary amount of work).

Python有三种模式via。当导入一个模块时,只有public模式是可访问的。因此private和protected模块不能从模块外部调用,即当它被导入时。

对于方法:(我不确定这是否是你想要的)

print_thrice.py

def private(method):
    def methodist(string):
        if __name__ == "__main__":
            method(string)
    return methodist
    
@private
def private_print3(string):
    print(string * 3)

private_print3("Hello ") # output: Hello Hello Hello

other_file.py

from print_thrice import private_print3
private_print3("Hello From Another File? ") # no output

这可能不是一个完美的解决方案,因为您仍然可以“看到”和/或“调用”该方法。不管怎样,它不会执行。