True privateness in Python

PEP 8 states that (emphasis mine):

We don't use the term "private" here, since no attribute is really private in Python (without a generally unnecessary amount of work).

I guess it refers to defining the actual class in some other language and then exposing only the public members to the interprete开发者_JAVA百科r. Is there some other way to achieve true privateness in Python?

I'm asking just out of curiosity.

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No, nothing is truly private in Python.

If you know the method name, you can get it.

I think you might come up with a clever hack, but it would be just that - a hack. No such functionality exists in the language.

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(Note: This is not "private" in the sense of C++/C#/Java type private, but it's close)

For a class, you can prefix a variable with '__'. This will cause Python to name mangle it so you can't accidentally call it from outside the class. For example:

class Test(object):
    def __init__(self):
        self.__number = 5

a = Test()
print a.__number # name error!

On the other hand, this isn't really private. You can access the number with:

print a.__Test_number

But it will prevent accidental mistakes, which is all private should be used for anyway. If it's prefixed with '__' and someone uses the code, their fault if that code breaks later on (they were warned).

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There is no true privateness. The best you could do is obfuscate the variable name and then create getters/setters or properties.

The only way to achieve this that I can think of this is to read/write a file every time you need to have access to that variable.

You could also write a program in another language that will only respond to certain classes. Not sure how to go about doing this, though.