[Python-Dev] Importing .pyc in -O mode and vice versa (original) (raw)

Aahz aahz at pythoncraft.com
Sun Nov 5 17:24:58 CET 2006

On Sun, Nov 05, 2006, "Martin v. L?wis" wrote:

Greg Ewing schrieb:

Fredrik Lundh wrote:

well, from a performance perspective, it would be nice if Python looked for fewer things, not more things. Instead of searching for things by doing a stat call for each possible file name, would it perhaps be faster to read the contents of all the directories along sys.path into memory and then go searching through that? That should never be better: the system will cache the directory blocks, also, and it will do a better job than Python will.

Maybe so, but I recently dealt with a painful bottleneck in Python code caused by excessive stat() calls on a directory with thousands of files, while the os.listdir() function was bogging things down hardly at all. Granted, Python bytecode was almost certainly the cause of much of the overhead, but I still suspect that a simple listing will be faster in C code because of fewer system calls. It should be a matter of profiling before this suggestion is rejected rather than making assertions about what "should" be happening.

Aahz (aahz at pythoncraft.com) <*> http://www.pythoncraft.com/

"In many ways, it's a dull language, borrowing solid old concepts from many other languages & styles: boring syntax, unsurprising semantics, few automatic coercions, etc etc. But that's one of the things I like about it." --Tim Peters on Python, 16 Sep 1993

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