["python","function","module","private"]
Defining private module functions in python

According to http://www.faqs.org/docs/diveintopython/fileinfo_private.html: Like most languages, Python has the concept of private elements: Private functions, which can't be called from outside their module However, if I define two files: #a.py __num=1 and: #b.py import a print a.__num when i run b.py it prints out 1 without giving any exception. Is diveintopython wrong, or did I misunderstand something? And is there some way to do define a module's function as private?
In Python, "privacy" depends on "consenting adults'" levels of agreement - you can't force it. A single leading underscore means you're not supposed to access it "from the outside" -- two leading underscores (w/o trailing underscores) carry the message even more forcefully... but, in the end, it still depends on social convention and consensus: Python's introspection is forceful enough that you can't handcuff every other programmer in the world to respect your wishes. ((Btw, though it's a closely held secret, much the same holds for C++: with most compilers, a simple #define private public line before #includeing your .h file is all it takes for wily coders to make hash of your "privacy"...!-))