too-many-newlines-at-end-of-file (W391)

Derived from the pycodestyle linter.

Fix is always available.

This rule is unstable and in preview. The --preview flag is required for use.

What it does

Checks for files with multiple trailing blank lines.

Why is this bad?

Trailing blank lines in a file are superfluous.

However, the last line of the file should end with a newline.

Example

spam(1)\n\n\n

Use instead:

spam(1)\n