Problem

My pytests take a while to complete, how can I speed up the process?

Solution

A fairly cheap solution is to use parallelization to run your tests on multiple CPUs instead of the 1 cpu used by default. To do so, you can install pytest-xdist. Once the extension is specified, all you need to do is add -n auto when you call pytest.

Another thing you should do that requires more effort is to investigate which of your tests are consuming a lot of CPU time to execute. To do so, use the --durations=0 flag when you call pytest. A report will be generated after your tests have run that lists how long setting up, running and tearing down each specific test took. The list is ordered from longest to shortest durations, meaning that the tests that have the most potential for being optimized will be at the top. You should focus on these tests because the longest one will determine how long it would take to run your tests even if you had an infinite amount of CPU cores.

Investigate why certain tests take a while to execute.

• Are some tests computing something that takes a while and is computed exactly the same way by multiple tests? Precompute this result once and share it between the different tests (think of it as a fixture).
• Are calls to a slow external API done? If you are not testing that the remote API is changing, store example responses and emulate receiving them.
• Is there a loop in the test that runs hundreds of thousands iterations while the same test could be executed with only a thousand iterations?

References

• https://github.com/pytest-dev/pytest-xdist

Problem

I want to include mypy as part of my CI pipeline but my existing code contains a lot (> 100, but < 500) of issues. How can I get started?

Solution

Create a minimalist configuration of mypy such that it will list issues that need to be fixed and return a non-zero exit code. Based on the problem definition, we assume that at this step you have more than 100 issues that are listed and that fixing those issues will take many hours you'd rather invest in improving the code than to fix typing issues.

Add a step in your CI pipeline that runs mypy and list all those issues. Verify that it indeed breaks the build.

Once you've satisfied yourself that CI fails, we will "fix" the mypy issues by adding the #type: ignore and/or # noqa comment after the offending lines with issues. This will have the effect of resolving all the currently found mypy issues, such that mypy should now return a zero exit code. With this, any future code that fails to pass the mypy check will break the build. This will allow you to use mypy from this point forward to check your types.

I suggest adding an additional comment such as # FIXME: TICKET-ID, where TICKET-ID refers to the id of a ticket in your issue tracking system that explains that you need to take care of this technical debt.

Always prefer to fix the issues instead of ignoring them. However, also consider whether fixing those issues is an appropriate use of your time when you want to introduce mypy (which should be as soon as possible in my opinion).

References

• https://mypy.readthedocs.io/en/stable/common_issues.html#silencing-linters

Problem

I have rated a lot of movies on Rotten Tomatoes and I'd like to export them to a text format. I also know PHP. How can I do that?

Solution

In 2013 I wrote Rotten Tomatoes ratings exporter for the purpose of exporting the movies I had rated into a format I could read and also store.

To automate the process of acquiring the ratings, I wrote a small class which needs information available in the site's cookies once you are logged in. With this information in hand, it is then possible to fetch the ratings from the website and store them in any desired format, given that the data returned to you is a plain PHP array.

References

• https://github.com/tomzx/rotten-tomatoes-exporter

Problem

I have movie ratings that I would like to import into IMDb. I also happen to know PHP. How can I do that?

Solution

In 2013 I wrote IMDb ratings importer for the purpose of importing ratings I had created in another system (Rotten Tomatoes). I wanted to import my ratings into IMDb so that I could use their statistics reporting tools, which let you see your distribution of ratings and the distribution of the release year of the movies you've seen. A friend of mine also had his bot send a message to our discussion channel whenever one of us would update their ratings after watching a movie.

The library is pretty straightforward. It expects you to provide it with a string that uniquely identifies your cookie on the server side. With an array of all the titles and ratings that you have, you can submit those ratings and the library's importer will take care of calling IMDb by finding the closest movie title and assigning it the desired rating.

References

• https://github.com/tomzx/imdb-importer

Problem

I use Visual Studio Code as my main editor and I am on Windows 7. I like to use emojis but those aren't properly rendered under Windows 7. Can I have pretty emojis in Visual Studio Code somehow?

Solution

I developed an extension in 2018 called Emoji which uses EmojiOne emojis to replace their non rendered equivalent in Visual Studio Code.

To do this, the extension makes use of the createTextEditorDecorationType method available on the window object in order to inject CSS that adds a background image where the text emoji would be rendered.

The extension listens to two events to determine in which editor it needs to do the replacement: window.onDidChangeActiveTextEditor and workspace.onDidChangeTextDocument. In the first case we update the editor that is now the active one, in the second, we update the active document when the text content changed.

Demo

Without the extension (before)

With the extension (after)

Reference

• Visual Studio Marketplace - Emoji extension
• Github repository - Emoji extension