trailing-comma-tuple / R1707#

Message emitted:

Disallow trailing comma tuple


In Python, a tuple is actually created by the comma symbol, not by the parentheses. Unfortunately, one can actually create a tuple by misplacing a trailing comma, which can lead to potential weird bugs in your code. You should always use parentheses explicitly for creating a tuple.

Correct code:

COMPASS = ("north", "south", "east", "west")

Problematic code:

COMPASS = "north", "south", "east", "west",  # [trailing-comma-tuple]

Created by the refactoring checker.