Python 313 Release Notes Verified Jun 2026

| Module | Change | |--------|--------| | argparse | BooleanOptionalAction now supports default=argparse.SUPPRESS | | copy | copy.replace() (PEP 712 – already in 3.12, finalized) | | random | New random.binomialvariate() | | os | os.pidfd_open() (Linux) | | time | time.time_ns() stability improvements | | sys | sys._is_gil_enabled() (to detect free-threaded mode) | | pathlib | Path.walk() (backported from 3.12, now stable) |

This change benefits long-running servers, GUI applications, and any process with large object graphs. python 313 release notes verified

Tier 2 optimizer improvements → 5–15% faster for some pure-Python loops. | Module | Change | |--------|--------| | argparse