Linting & Formatting 🎀

Linters perform static analysis of source codes and check for symantic discrepancies. When you lint your code, it’s passed through a basic quality checking tool that provides instructions on how eliminate basic syntactic inconsistencies.

Formatters are similar tools that tries to restructure your code spacing, line length, argument positioning etc to ensure that your code looks consistent across different files or projects.

Python offers you a plethora of linters and formatters to choose from. Flake8, pyflakes, pycodestyle, pylint are some of the more widely used linters and black, yapf are two newer members in the code formatting space. However, not to bombard you with a deluge of information, we are taking an opinionated route that gets the job done without a hitch. Let’s talk about Flake8 and Black.

Flake8

Flake8 is a Python linting library that basically wraps three other linters, PyFlakes, pycodestyle and Ned Batchelder’s McCabe Script. It’s one of the better linters out there that has very low false positive rate. It checks your code base against PEP8 programming style, programming errors (like “library imported but unused” and “Undefined name”) and cyclomatic complexity.

Imgur

For more details on the nitty gritties of flake8, check out their github project here.

Black

Black is known as the uncompromised Python code formatter. Unlike flake8 or pycodestyle, it doesn’t nag you when there are style inconsistencies. It just fixes them for you. Black does not have a lot of options to tinker with and has a lot of opinion on how your code should look and feel. You might not always agree with the decisions that black takes for you but if you can get along with the style that black imposes on you, it can take care of the unnecessary hassles of formatting your codes to keep it conistent across multiple projects or organization.

Imgur Before formatting with black

Imgur After formatting with black

Setting Up Linters in VS Code

Luckily VS Code comes with both flake8 and black formatter lurking in the settings. To set them up:

  • Press ctrl+, to fire up the settings panel

  • Search for flake8 in the search panel

  • Enable the option Python>Linting:Flake8 Enabled

  • Search for black and select black from the dropdown called Python>Formatting:Provider

Doing the above will set flake8 and black to lint and format your script on a project basis. You have to install flake8 and black in your environment via pip install flake8 and pip install black respectively. If you want to set them up globally and don’t want to worry about formatting ever again, you have set up their global paths. To do so:

  • Deactivate your environment

  • Install flake8 and black globally via pip3 install flake8 and pip3 install black

  • On the terminal write whereis flake8 and whereis black

  • You should see their global paths Imgur

  • Now go to the settings and search for flake8 and paste your flake8 path in Python › Linting: Flake8 Path option Imgur

  • Copy black path and paste them in Python › Formatting: Black Path option Imgur