Python’s dicts for many years did not return keys in insertion order (since Tim Peters improved the hash in iirc 1.5 until Raymond Hettinger improved it further

Python’s dicts for many years did not return keys in insertion order (since Tim Peters improved the hash in iirc 1.5 until Raymond Hettinger improved it further in iirc 3.6). After the 3.6 changed, they were returned in order. And people started relying on that - so at a later stage, this became part of the spec.