Mailman 3 January 2022 - code-quality

Coverage not catching execution in my Flask app
by Skip Montanaro 22 Jan '22

22 Jan '22

I have a simple little Flask app and created a suitably simple test script, aimed at making sure I covered much of the executable code. It fires up the app with coverage enabled and hits it with a bunch of requests, then exits. When testing, I have coverage enabled: CMD="$(which flask) run -h localhost -p $PORT" if [ "x$DOCOVER" = "xtrue" ] ; then coverage run -a $CMD else $CMD fi Coverage seems to do the right thing, creating a .coverage file on exit, and when I run the annotate, report, or html commands it does the right thing. Still, it never actually marks any statements within functions as having been executed. Here's coverage from a manual run where I poked the server with three debug endpoints: > if FLASK_DEBUG: > @app.route("/env") > def printenv(): ! return jsonify(dict(os.environ)) > @app.route('/api/help') > def app_help(): > """Print available functions.""" ! func_list = {} ! for rule in app.url_map.iter_rules(): ! if rule.endpoint != 'static': ! func_list[rule.rule] = str(app.view_functions[rule.endpoint]) ! return jsonify(func_list) > @app.get('/shutdown') > def shutdown(): ! func = request.environ.get('werkzeug.server.shutdown') ! if func is None: ! raise RuntimeError('Not running with the Werkzeug Server') ! func() ! return 'Server shutting down...\n' Clearly, coverage noticed the action which happened during import, but despite the fact that I really did request /env, /api/help, and /shutdown, it never thought any of them were called. Any idea what I'm missing? Thx, Skip Montanaro

2 3

could itertools.cycle not make a copy of the iterable ?
by jerome.guay＠protonmail.com 19 Jan '22

19 Jan '22

Hi everyone, first I'm not quite sure if this is the right place to make this kind of suggestion/ask question but, `itertools.cycle` makes a copy of the iterable its given and as the note says: this may require significant auxiliary storage. Maybe I don't see the reason why this is nescessary but, shouldn't this work just as well: ``` def cycle(iterable): # cycle('ABCD') --> A B C D A B C D A B C D ... while iterable: for element in iterable: yield element ``` Instead of the current: ``` def cycle(iterable): # cycle('ABCD') --> A B C D A B C D A B C D ... saved = [] for element in iterable: yield element saved.append(element) while saved: for element in saved: yield element ```

4 4

Flake8: how to compose project and personal configurations?
by Xavier Morel 14 Jan '22

14 Jan '22

Hello, Sorry for the bother but I had a question about balancing personal and project uses of flake8: on a project we're trying to progressively introduce flake8 (so enabling a subset of all checks on a subset of all files). We tried adding a config doing via "select" and "ignore" in the existing setup.cfg, however this turned out to break a lot of people's linting, as their editor simply ran flake8 in the default configuration and they used that for their contributions (even though it was not checked project-wide). Looking further into this, it looks like recent versions of flake8 have "extend-ignore" and "extend-select" to avoid breaking things locally, however there are a few issues I don't know how to fix, or whose semantics is not clear: - according to the documentation, CLI values have the highest priority, but how does that work with select versus extend-select? Is `--select` used as the baseline then `extend-select` from the configuration files gets added to that? - is `--select ''` the proper way to deselect everything? - is there a way to make exclusions error-specific, or is an other workaround necessary to add large sections of the project to exclusions for the CI, but not prevent linting for people? Regards, Xavier

4 5

"Subscribing" to Releases
by Levi Muniz 06 Jan '22

06 Jan '22

Hi there, First off, thank you for the awesome flake8 project! My team has just started using it and I expect we will only use it more moving forward. I wanted to ask if there was a way I could be notified of releases, such as a mailing list I can subscribe to? I'm also happy to use GitHub's "watch" function for releases, but tags don't count as releases. Thanks again! Levi Muniz DevOps Engineer levi.muniz(a)Quantum.com<mailto:levi.muniz@Quantum.com> [twitter]<https://twitter.com/quantumcorp> @QuantumCorp<https://twitter.com/quantumcorp> [linkedin]<https://www.linkedin.com/company/quantum> QuantumCorp<https://www.linkedin.com/company/quantum> Quantum.com<https://www.quantum.com/?utm_source=quantum-email&utm_medium=email-signatur…> [cid:image003.jpg@01D80153.D4246D20]<https://www.quantum.com/?utm_source=quantum-email&utm_medium=email-signatur…> The information contained in this transmission may be confidential. Any disclosure, copying, or further distribution of confidential information is not permitted unless such privilege is explicitly granted in writing by Quantum. Quantum reserves the right to have electronic communications, including email and attachments, sent across its networks filtered through security software programs and retain such messages in order to comply with applicable data security and retention requirements. Quantum is not responsible for the proper and complete transmission of the substance of this communication or for any delay in its receipt.

6 7