Braces were claimed by dicts first; a set has to be spelled out as set()

Both dict and set literals use curly braces. {1, 2} is a set and {"a": 1} is a dict, but with nothing inside Python has to pick, and dicts got there first. Always check what a literal produced with type() when in doubt.

print(type({}), type({1}))

Read it once, then a question tests whether the trick stuck.