This is a personal list of what I really liked (and disliked) about each release of Python.

3.11

• 19% speed improvement
• more informative KeyError handling
• TOML batteries included

3.10

• Better messages for syntax errors e.g. "SyntaxError: { was never closed" for line 1 where the curly brace started rather than "SyntaxError: '{' was never closed" for line 3 which was an innocent line
• Note – Structural Pattern Matching should be considered more of an anti-feature given its problems and its limited benefits for a dynamically typed language like Python

3.9

• String methods removesuffix and removeprefix (NOT same as rstrip() as that works on the letters). Note – absence of underscores in method names
• Union operator for dicts (new dict which is an update of the first by the second) e.g. up_to_date_dict = orig_dict | fresh_dict

3.8

• f-strings support e.g. f"{var=}"
• walrus operator := (an antifeature with costs that outweigh benefits)
• positional-only parameters (so can change names without breaking code) – like extending list comprehensions to cover dictionaries, sets, and tuples it completes the coverage as you’d expect

3.7

• Nothing

3.6

• f-strings (massive)
• Underscores in numbers e.g. 3_500_000 – as a data guy this is huge