reinvent-check

Finds Python functions that were written twice under different names. Paste several files below (start each with a # file: name.py line) or load .py files from disk, then run. Everything runs in your browser with Pyodide; no code is uploaded.

load .py files min size (AST nodes)

Python is loading (about 10 MB, once).

How it decides two functions are the same

Each function is parsed with Python's own ast module. The docstring, decorators, type hints and line numbers are dropped.
Arguments and local variables are renamed by order of first use, so total_due(items, tax_rate) and order_value(lines, vat) collapse to the same tree.
Globals, called helpers, attribute names and constants keep their names, so the same shape calling a different helper is not a match.
Limit: exact structure only. Reordered statements or one changed constant are not reported.

Command line

uv run main.py src/ --min-nodes 12 prints the groups; --json for machine output.
Exit code 1 when duplicates exist, so it can gate CI. Folders named vendor, .venv, site-packages and node_modules are skipped.
The source is shown below; it is the exact file this page runs.

main.py