[Python-Dev] __pycache__ creation

Isaac Morland ijmorlan at uwaterloo.ca
Mon Mar 22 18:28:25 CET 2010

On Mon, 22 Mar 2010, Antoine Pitrou wrote:

> Oh, and by the way, there can be a race condition between __pycache__
> creation and deletion (if it fails the test), where an attacker can stuff
> a hostile pyc file in the directory in the meantime (and the deletion
> then fails because the directory isn't empty).

Would creating it under a different name and then renaming help with this?

> IMO, all these issues militate for putting __pycache__ creation out of
> the interpreter core, and in the hands of third-party package-time/
> install-time tools (or distutils).

Speaking only for myself, but really for anybody who likes tidy source 
directories, I hope some version of the __pycache__ proposal becomes part 
of standard Python, by which I ideally mean it's enabled by default but if 
that is just not a good idea then at most it should be required to set a 
command-line option to get this feature.

If I just want to write some .py code and run it, I don't see why my 
directories need to clutter up with .pyc files.  I've previously suggested 
a Python version of javac's -d ("destination directory") option, but 
putting all the .pyc's in a __pycache__ directory per source directory is 
good enough to make me happy (and is Pythonically simple, in my opinion).

Isaac Morland			CSCF Web Guru
DC 2554C, x36650		WWW Software Specialist

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