Symptoms

  • Environment detection scripts mistakenly treat Python 3.10 as Python 3.1.
     

  • Conditional logic using string comparison produces wrong results:

if platform.python_version() < "3.9":
    ...

  • may behave incorrectly under 3.10.

Why

Some tools and scripts naïvely compared version strings rather than parsing them as tuples of integers. String comparison is lexicographical — "3.10" comes before "3.9" because "1" is less than "9" in the second character position.

This issue hit older pip installers, tox configs, and internal deployment scripts that didn’t account for double-digit minor versions. It was also noted in the Python 3.10 porting guide.

Fix / Best Practices

1) Use sys.version_info for comparisons

import sys

if sys.version_info < (3, 9):
    print("Python < 3.9 detected")

sys.version_info returns a tuple-like struct: (major, minor, micro, releaselevel, serial) — safe for numeric comparison.

2) For packaging, use packaging.version

from packaging import version
import platform

if version.parse(platform.python_version()) < version.parse("3.9"):
    ...

3) Update tooling

  • Upgrade pip, setuptools, tox, and CI runners — newer versions handle 3.10+ correctly.

  • Audit shell scripts and config files for raw string comparisons like:

if [ "$(python3 --version)" \< "Python 3.9" ]; then ...

How to Avoid This in the Future

  • Always parse versions numerically, not lexicographically.
     

  • Test your version checks against upcoming release candidates (e.g., 3.13.0rc1).
     

  • Track the Python Developer’s Guide release calendar to anticipate double-digit minors.