[3.11] gh-91539: improve performance of get_proxies_environment (GH-91566)

[miss-islington]

• improve performance of get_proxies_environment when there are many environment variables

• 📜🤖 Added by blurb_it.

• fix case of short env name

• fix formatting

• fix whitespace

• whitespace

• Update Lib/urllib/request.py

Co-authored-by: Carl Meyer carl@oddbird.net

• Update Lib/urllib/request.py

Co-authored-by: Carl Meyer carl@oddbird.net

• Update Lib/urllib/request.py

Co-authored-by: Carl Meyer carl@oddbird.net

• Update Lib/urllib/request.py

Co-authored-by: Carl Meyer carl@oddbird.net

• whitespace

• Update Misc/NEWS.d/next/Library/2022-04-15-11-29-38.gh-issue-91539.7WgVuA.rst

Co-authored-by: Carl Meyer carl@oddbird.net

• Update Lib/urllib/request.py

Co-authored-by: Carl Meyer carl@oddbird.net

Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Co-authored-by: Carl Meyer carl@oddbird.net
(cherry picked from commit aeb28f5)

Co-authored-by: Pieter Eendebak pieter.eendebak@gmail.com

• Issue: speed up urllib.request.getproxies_environment #91539

[orsenthil]

LGTM

[miss-islington]

Sorry, I can't merge this PR. Reason: Head branch was modified. Review and try the merge again..

[ambv]

This is a perf optimization, currently we're accepting changes for 3.11.1+ which are bug fixes only. Therefore, this change cannot be included in 3.11.

[FrederikP]

I was wondering whether this will be merged at some point? It seems to be included in latest python 3.10 but not latest 3.11, if I saw it correctly.
Thanks

[morotti]

so sad this fix was merged in master and merged in 3.10 but the merged in 3.11 was blocked for no reason :( :( :(

requests is using this urllib get_proxies_environment function to get proxy settings on every HTTP request.
when you install packages with pip install xxx, about 5% of the run time is just fetching proxy settings again and again through this function.