RUFF C408 rule (unnecessary-collection-call)

[bigcat88]

This rule checks for unnecessary dict(), list() or tuple() calls that can be rewritten as empty literals.

Why is this bad?

It's unnecessary to call, e.g., dict() as opposed to using an empty literal ({}). The former is slower because the name dict must be looked up in the global scope in case it has been rebound.

Examples:

dict()
dict(a=1, b=2)
list()
tuple()

Use instead:

{}
{"a": 1, "b": 2}
[]
()

Ruff's docs link