Let’s continue analysis from Performance Analysis of Python’s dict() and {} and dive deeper into the Python’s internal types for dict.

Some time ago, during a code review, I had a discussion with a colleague of mine about preferring dict() over {} in new Python code. They argued that dict() is more readable — and expresses intent more clearly — therefore should be preferred. I wasn’t convinced by that, but at that time I didn’t have any counterarguments, so I passed.

Yet that made me wonder: what’s the difference between the dict type and {} literal expression?