[Python-Dev] Investigating time for import requests (original) (raw)

Glenn Linderman v+python at g.nevcal.com
Sun Oct 1 22:49:04 EDT 2017

On 10/1/2017 7:34 PM, Nathaniel Smith wrote:

Another major slowness comes from compiling regular expression. I think we can increase cache size of re.compile and use ondemand cached compiling (e.g. re.match()), instead of "compile at import time" in many modules. In principle re.compile() itself could be made lazy -- return a regular exception object that just holds the string, and then compiles and caches it the first time it's used. Might be tricky to do in a backwards compatibility way if it moves detection of invalid regexes from compile time to use time, but it could be an opt-in flag. Would be interesting to know how many of the in-module, compile time re.compile calls use dynamic values, versus string constants. Seems like string constant parameters to re.compile calls could be moved to on-first-use compiling without significant backwards incompatibility impact if there is an adequate test suite... and if there isn't an adequate test suite, should we care about the deferred detection? -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.python.org/pipermail/python-dev/attachments/20171001/adbc994a/attachment-0001.html>

More information about the Python-Dev mailing list