trailing-comma-on-bare-tuple (COM818)

Derived from the flake8-commas linter.

What it does

Checks for the presence of trailing commas on bare (i.e., unparenthesized) tuples.

Why is this bad?

The presence of a misplaced comma will cause Python to interpret the value as a tuple, which can lead to unexpected behaviour.

Example

import json


foo = json.dumps({"bar": 1}),

Use instead:

import json


foo = json.dumps({"bar": 1})

In the event that a tuple is intended, then use instead:

import json


foo = (json.dumps({"bar": 1}),)