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Linting and Formatting

Linting your code¶

For linting, we currently make use of ruff to perform checks, and if desired, some fixes for your code.

For a standard formatter, we use black against the code base.

These are used to ensure we produce readable, maintainable, and more consistent code.

To quickly run both the linter and formatter, you can source the linting bash script (shown below). The -f flag can be called to run automatic fixes with ruff. If you simply wish for ruff to print the errors it finds to the console, remove this flag.

source scripts/lint_and_format.sh -f  # with the fix flag

source scripts/lint_and_format.sh  # without
You can also run ruff and black separately from a terminal instance.

Black can be run using: black . or to direct it at specific folders: black splink/

and ruff requires: ruff --fix . for automatic fixes and error printouts or ruff --show-source . for error checking.

Error Suppression¶

Should the linter be screaming at you about an "error" that you do not wish to change within the code base, you can ignore a single instance of a violation by using the # noqa [ERROR CODE] flag at the end of a code line.

For example, let's say we have a print() statement buried somewhere in our code that we wish to keep, as it's useful in detecting whether a function has worked as expected.

We can remove the lint detection of this line by adding any of the following flags: 

# Ignore T201.
print("Ignore me!")  # noqa: T201

# Ignore T201 and T203.
print("Ignoring multiple rules")  # noqa: T201, T201

# Ignore _all_ violations.
print("Is there any point in this linter?")  # noqa

Another useful example of this can be found within our backend comparison scripts. As we are merely importing and not subsequently using a series of functions and classes, the linter throw an error - F401.

To suppress this, we simply add the # noqa: F401 flag as a comment next to the code chunk or line we wish to suppress checks for.

For a more detailed overview of error suppression, see the ruff documentation.

Additional Rules¶

ruff contains an extensive arsenal of linting rules and techniques that can be applied.

Should there be a formatting concern that you feel hasn't been taken into account, please do check the full set of rules to determine whether this is supported by ruff and subsequently raise a pull request featuring this new rule.

Adding Additional Rules

To add additional rules to the linter, you simply need to:

  1. Open up pyproject.toml and navigate to [tool.ruff].
  2. In the select block where we currently have # pyflakes, # Pycodestyle, etc. simply add your additional argument code, using the ruff rules page as a reference.
  3. Add in a linting violation and run the lint_and_format.sh script to test your change is working as expected.