# Python 3.11+ from asyncio import gather, sleep async def risky_task(name, fail): await sleep(0.1) if fail: raise ValueError(f"name failed") return name
Released in October 2022, Python 3.11 stands as a landmark update for the language. While the world has since moved to 3.12 and 3.13, 3.11 remains the bedrock for many production systems due to its maturity and significant, measurable improvements over Python 3.10. This update focused heavily on two core pillars: execution speed and error clarity .
Before 3.11, if you ran multiple tasks and two failed with different errors, Python would raise the first exception and swallow the second. You would lose debugging information. python 3.11
import tomllib with open("config.toml", "rb") as f: config = tomllib.load(f) print(config["tool"]["poetry"]["name"])
If you are still on Python 3.8 or 3.9, here is why you should make the jump to 3.11 (or later). The headline feature of Python 3.11 is the result of Microsoft’s "Faster CPython" team, led by Mark Shannon. For years, Python developers accepted the trade-off of slower execution for rapid development speed. Python 3.11 narrowed that gap significantly. # Python 3
Python 3.11 fixes this. When an error occurs, the interpreter now points an arrow ( ^ ) at the specific expression that failed, not just the line number.
async def main(): tasks = [risky_task("A", True), risky_task("B", False), risky_task("C", True)] try: results = await gather( tasks, return_exceptions=False) except ValueError as eg: for exc in eg.exceptions: print(f"Handling: exc") Handling: A failed Handling: C failed Before 3
Notice the except* (star-except) syntax. It catches all ValueErrors inside the group without breaking the successful execution of task "B". Ask any developer: "What is the worst part of Python?" Many will answer: Tracebacks that only tell you the line, not the column.