duplicate-value (B033)

Derived from the flake8-bugbear linter.

What it does

Checks for set literals that contain duplicate items.

Why is this bad?

In Python, sets are unordered collections of unique elements. Including a duplicate item in a set literal is redundant, as the duplicate item will be replaced with a single item at runtime.

Example

{1, 2, 3, 1}

Use instead:

{1, 2, 3}