What does __ALL__ mean?

[Erik Max Francis]

John Roth wrote:

> If you want to maintain absolute control over the API, yes.

Note that it doesn't prevent people from manipulating the "non-public"
contents if they know their names, nor does it prevent them from
appearing as module attributes with dir, etc.  __all__ simply affects
what is important with from module import *, and that is all:

max at oxygen:~/tmp% cat > sample.py
__all__ = ['x', 'y', 'z'] 
x, y, z = range(3) 
a, b = range(2)
_p, _q, _r = range(3)
^D
max at oxygen:~/tmp% python
Python 2.2.2 (#2, Oct 14 2002, 17:32:20) 
[GCC egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import sample
>>> from sample import *
>>> dir()
['__builtins__', '__doc__', '__name__', 'sample', 'x', 'y', 'z']
>>> dir(sample)
['__all__', '__builtins__', '__doc__', '__file__', '__name__', '_p',
'_q', '_r', 'a', 'b', 'x', 'y', 'z']
>>> sample.a
0
>>> sample._r
2

I'm sure you know this, I'm just clarifying for the original poster.

-- 
 Erik Max Francis / max at alcyone.com / http://www.alcyone.com/max/
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