During a code review, a colleague, Zachary Paden, asked me why I was calling the typing.cast function on my variables rather than creating temporary variables just to type hint. Well, just as he didn’t know about cast, I didn’t know that this approach worked. Being the nerdz that we are, he decided to measure the performance of each approach.
Tag: Python
bookmark_borderboto3 – From monkeypatch to moto
Today, at the suggestion of a college (Zachary Paden), I contemplated the idea of migrating my tests using python/monkeypatch to moto. Here I will share my journey and observations.
Continue reading “boto3 – From monkeypatch to moto”bookmark_borderCreating a pydantic model for GIS polygons
In this article, I will explain how to create a pydantic model to validate and create polygons for GIS (geographic information systems).
Continue reading “Creating a pydantic model for GIS polygons”bookmark_borderHow to integrate mypy in existing projects
Here is simply how I went about integrating mypy into a few projects. This post assumes you are using git and have a test system in place.
Continue reading “How to integrate mypy in existing projects”bookmark_borderPython poetry: Explanations and tips
For those who are used to using a “basic” virtual environment with virtualenv, poetry can be confusing. Here are some clarifications and tips on using poetry.
Continue reading “Python poetry: Explanations and tips”bookmark_borderMinimizing the size of lambdas by avoiding having boto3 and its stubs in the deployment package
If you are having problems with AWS lambdas exceeding the 250MB limit, here is a tip that might help.
Continue reading “Minimizing the size of lambdas by avoiding having boto3 and its stubs in the deployment package”bookmark_borderpython poetry 1.0.0 private repo issue fix
On December 12th 2019, poetry v1.0.0 was released. With it, came a bad surprise for me: My CI/CD jobs as well as my Docker image builds started failing.
After investigating, I’ve found out that the password key/value was now missing from the .config/pypoetry/auth.toml file. Digging some more, I’ve found out that poetry relies on a library called keyring to manage passwords.
Here is what I did to fix the problem.
First, I’ve noticed that poetry falls back to the previous method if keyring returns RuntimeError when it is called. Nice. It turns out that keyring comes with a backend aptly named “fail” which does that whatever the call is. So, it’s only a matter of configuring it.
As the keyring documentation states it, run python -c "import keyring.util.platform_; print(keyring.util.platform_.config_root())" to find where to put the configuration file. Then, in that directory, create keyringrc.cfg and put the following content in it:
[backend]
default-keyring=keyring.backends.fail.Keyring
That’s it. Now you can call poetry config http-basic.... the same way you used to and the password will be stored in auth.tomllike before.
bookmark_borderPython code formatters comparison: Black, autopep8 and YAPF
Following some discussions at work and the will of the team to adopt a python code formatter, I set out to explore some of them. No need to say, the contenders had to aim towards pep8 compliance. Here are my findings on three of them.
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bookmark_borderPython logging to stackdriver
I recently deployed a python application in google app engine / container engine. When I went to check the logs, everything was logged at the “ERROR” level even though my application uses python logging properly. As far as I know there are 2 ways to fix that:
- Use the stackdriver client, which requires an additional dependency and somewhat binds your program to google app engine.
- Format the logs in a way that stackdriver can parse them, which is easily configurable.
bookmark_borderRecipe: Testing multiple python versions with pyenv and tox
If you develop a ton of python applications and you need to test under a lot of different versions, and by a lot I mean overlapping major/minor versions (like 3.5.3 and 3.5.4), then a good option is to use pyenv. Along with tox, you can easily test your application against various major/minor versions.
Here is how to do it.
Continue reading “Recipe: Testing multiple python versions with pyenv and tox”