flake8-plus 0.2.0

Flake8 plugin adding PEP8-compliant vertical whitespacing rules

Flake8-plus

Flake8-plus is a plugin for Flake8 that detects incorrect amounts of vertical whitespace before the first toplevel import statement. By default, the plugin issues a warning if there are blank lines immediately preceding the first toplevel import. The plugin can be configured to expect any number of blank lines.

Installation

Flake8-plus can be installed from PyPI using pip:

$ pip install flake8-plus

You can verify that it has been installed as follows (the version numbers you see may vary):

$ flake8 --version
5.0.4 (flake8-plus: 0.1.0, mccabe: 0.7.0, pycodestyle: 2.9.1, pyflakes: 2.5.0)

Configuration

You can set the required number of blank lines before the first import. This can be done from the command line:

$ flake8 --blanks-before-imports 1

Or from one of the setup.cfg, tox.ini, or .flake8 files:

[flake8]
blanks-before-imports=1

Why no blank lines?

Neither Black, Flake8 nor Pylint enforces a specific number of blank lines preceding the first import and consequently there seems to be no consensus or standard. The table below shows the frequency of the number of blank lines before the first toplevel import statement in the code bases for Black, Flake8 and Pylint (as of October 2022).

Package	Total files	0 blanks	1 blank	2 blanks	Folder
Black	33	21	12	0	src
Flake8	32	32	0	0	src/flake8/
Pylint	177	3	170	4	pylint

Clearly, there is no real consensus. Black seems undecided, Flake8 consistently uses 0 blanks, and Pylint seems to prefer 1 blank line. However, it's worth noting that the Pylint code does not consistently include module docstrings (thereby breaking pylint(missing-module-docstring)). For that reason, and also because this is a Flake8 plugin, the plugin follows the style of Flake8 as the default.

Reported problems

Code	Description
PLU001	"expected {} blank lines before first import, found {}"