Python 3.10 Release History

Python 3.10 (released October 4, 2021) introduced one of the most significant syntax upgrades in recent years, along with improvements in typing and debugging.

Major Highlight: Structural Pattern Matching (match / case)

The biggest feature is PEP 634–636, introducing pattern matching.

This is not just a switch statement — it allows matching based on data structure and shape:

• Supports sequences, mappings, and class instances
• Allows unpacking values directly into variables
• Supports nested patterns and guards

def http_error(status):
    match status:
        case 400:
            return "Bad request"
        case 404:
            return "Not found"
        case _:
            return "Something's wrong"

Pattern matching enables programs to branch based on structure and extract values declaratively ([Python documentation][1])

Language and Typing

• PEP 604: Union types using |
• PEP 612: ParamSpec for callable typing
• PEP 613: Explicit type aliases
• PEP 647: User-defined type guards ([Python documentation][1])

Interpreter and Debugging

• PEP 626: Precise line numbers:

  • Better debugging and coverage tools

• Improved traceback accuracy and diagnostics ([Python documentation][1])

Standard Library

• PEP 618: zip(strict=True) for safer iteration
• Improvements across typing, contextlib, and others ([Python documentation][1])

Performance Improvements

• Faster:

  • str, bytes, bytearray (~30–40%)
  • Attribute access (~30–40%)

• Faster module startup (runpy)

• General interpreter optimizations ([Python documentation][1])

Deprecations

• PEP 632: distutils deprecated
• PEP 644: OpenSSL 1.1.1+ required
• Removal of legacy Unicode APIs ([Python documentation][1])

Subversions log

• 3.10.19 (Oct 2025) — final security updates
• 3.10.14 (Mar 2024) — security fixes (CVE)
• 3.10.9 (Dec 2022) — urllib security patch
• 3.10.4 (Mar 2022) — asyncio memory fixes
• 3.10.0 (Oct 2021) — initial release

Official 3.10 documentation