Python Upgrade Lint: Removed Stdlib 3.12-3.14

It reads a Python .py file and marks every line that uses a standard-library module or API removed in Python 3.12, 3.13 or 3.14, such as cgi, imp, distutils, telnetlib, the old unittest aliases or ast.Str. It checks 43 rules. For each finding it shows the line number, the version that removed it, the PEP or What's New source, and the replacement to use.

Python developers and platform teams moving services off Python 3.10 before its October 2026 end of life, and anyone upgrading a Django, Flask, script or data-pipeline codebase to Python 3.12, 3.13 or 3.14. It also suits reviewers of AI-written Python, because assistants trained on older code can still produce imports such as cgi, imp or distutils.

A chatbot lists removed modules from memory. It does not read your file line by line, and it often mixes up the version: imp was removed in 3.12, cgi in 3.13 and ast.Str in 3.14. Running the new interpreter only shows the first ModuleNotFoundError, one at a time. This checker applies one fixed table of 43 rules and reports every hit at once.

Free, with no key: check one open .py file against all 43 rules, in VS Code or pasted into the web page, and pick 3.12, 3.13 or 3.14 as the target. The paid licence ($29 once, one key per person or team seat) adds a whole-workspace sweep in one pass and a Markdown upgrade report for each target version to attach to the migration ticket.

By hand, a developer greps for each removed module and API, cross-checks the Python What's New pages for 3.12, 3.13 and 3.14, and then fixes the hits. The US median software developer wage is $63.98 an hour (BLS, May 2024), so every hour of searching costs about that much. On our 46-line sample file the checker reported 14 findings at once.