# nedbat/byterun

A Python implementation of a Python bytecode runner

Repository: https://github.com/nedbat/byterun
Canonical: https://ross.abutalabs.com/products/byterun
Language: Python
License: MIT
License Family: permissive
Last push: 2024-07-22T12:42:48+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 4979, "days_push": 772, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1360, forks 272 (observed 2026-08-28T04:04:29.786872+00:00)

## What it is
Byterun is a pure-Python implementation of a Python bytecode execution virtual machine. It was created to understand CPython bytecodes, originally to help fix branch coverage bugs in coverage.py.

## Use cases
- understand how python bytecode executes
- run python bytecode in pure python
- learn how a python interpreter works
- debug coverage measurement of branches
- experiment with a python virtual machine implementation

## When to choose
- you want to study or teach how CPython's bytecode VM works
- you need a pure-Python interpreter for bytecode analysis or experimentation

## When to avoid
- you need a fast, production-grade Python runtime
- you need full compatibility with the latest CPython bytecode

## Facets
- artifact type: library
- maturity: maintenance
- function: interpreter, parser, developer-tools
- domain: programming-languages, compilers, developer-tools, education
- platform: python, cross-platform
- tags: bytecode, virtual-machine, python-internals, educational

## Member repositories
- nedbat/byterun (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:29.786872+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T04:41:39.893545+00:00, confidence not recorded.
  - readme: https://github.com/nedbat/byterun (fetched 2026-08-28T04:04:29.786872+00:00, sha 42e5ccd3e0a4)
- Data as of 2026-08-30T08:39:29.467469+00:00.