Provided better example for logging cookbook (GH-101164)

[galqiwi]

This change is trivial, so, according to guidelines, i haven't created an issue.

I just made a small fix to the code from logging cookbook. The rotator function should compress file. And, to compress file, you need to use gzib library, not zlib.

To save you some time, this fact is clearly stated in zlib docs

For reading and writing .gz files see the gzip module.

[cpython-cla-bot]

All commit authors signed the Contributor License Agreement.

[vsajip]

While we're doing this, we might as well change this snippet into a runnable script:

import gzip
import logging
import logging.handlers
import os
import shutil

def namer(name):
    return name + '.gz'

def rotator(source, dest):
    with open(source, 'rb') as f_in:
        with gzip.open(dest, 'wb') as f_out:
            shutil.copyfileobj(f_in, f_out)
    os.remove(source)

rh = logging.handlers.RotatingFileHandler('rotated.log', maxBytes=1024, backupCount=5)
rh.rotator = rotator
rh.namer = namer
root = logging.getLogger()
root.setLevel(logging.INFO)
root.addHandler(rh)
f = logging.Formatter('%(asctime)s %(message)s')
rh.setFormatter(f)
for i in range(1000):
    root.info(f'Message no. {i + 1}')

and show that it seems to work:

$ gzip -dc rotated.log.1.gz | head -n 5
2023-01-19 21:55:12,677 Message no. 955
2023-01-19 21:55:12,678 Message no. 956
2023-01-19 21:55:12,678 Message no. 957
2023-01-19 21:55:12,678 Message no. 958
2023-01-19 21:55:12,709 Message no. 959

[bedevere-bot]

A Python core developer has requested some changes be made to your pull request before we can consider merging it. If you could please address their requests along with any other requests in other reviews from core developers that would be appreciated.

Once you have made the requested changes, please leave a comment on this pull request containing the phrase I have made the requested changes; please review again. I will then notify any core developers who have left a review that you're ready for them to take another look at this pull request.

And if you don't make the requested changes, you will be put in the comfy chair!

[galqiwi]

I have made the requested changes; please review again

[bedevere-bot]

Thanks for making the requested changes!

@vsajip: please review the changes made to this pull request.

[miss-islington]

Thanks @galqiwi for the PR, and @vsajip for merging it 🌮🎉.. I'm working now to backport this PR to: 3.10.
🐍🍒⛏🤖

[miss-islington]

Thanks @galqiwi for the PR, and @vsajip for merging it 🌮🎉.. I'm working now to backport this PR to: 3.11.
🐍🍒⛏🤖

[bedevere-bot]

GH-101183 is a backport of this pull request to the 3.10 branch.

[bedevere-bot]

GH-101184 is a backport of this pull request to the 3.11 branch.

[vsajip]

@galqiwi : Thanks for this patch, now merged, but you signed the CLA using your @yandex-team.ru. However, this information was lost when the PR was squashed and merged, and the backport PRs can't be merged because they only have your GitHub profile email address galqiwi@galqiwi.ru, which is not recorded as having signed the CLA. Can you please sign the CLA again, but using your @galqiwi.ru email? Thanks!