pyc_revive

.pyc -> .py reconstructor. no uncompyle6. no pycdc. no xdis.

use

python -m pyc_revive my file.pyc
python -m pyc_revive ./dist/app.pyc --out ./revived.py

input handling: exact path, spaces with no quotes, basename search in cwd + all subfolders + parent folder.

versions

every CPython from 2.0 through 3.15 resolves by magic number (pymagic.py, full table + nearest fallback + header sizes).

two backends, one pipeline:

• native: .pyc matches the running interpreter. stdlib marshal loads the code object, stdlib dis disassembles. zero dependencies.
• pycdas: anything else. the bundled pycdas.exe disassembles the foreign version, pycdas_parser.py parses the dump into code trees, shim.py adapts them to the pipeline. everything downstream (normalize, segment, translate, CFG, emit, verify x3) runs unchanged.

pipeline

1. find file (finder.py)
2. detect version via magic (pymagic.py)
3. load: native marshal, else pycdas backend (loader.py, pycdas_parser.py, shim.py)
4. disassemble + abstract (bytecode.py: Inst, EditableBytecode, opcode/oparg/value-stack/metadata tables)
5. normalize / mask consts + names (normalizer.py)
6. opcode-aware B/I/E segmentation (segmenter.py)
7. statement translation (translator.py: stack machine, defaults recovery, lambdas inline, 2.x print/exec/class ops)
8. control-flow graph from jumps (cfg.py: if/for/while/try/except-as (bare except: too)/with/finally, clauses + clusters, 3.11+ exception table, SETUP-region splits)
9. emit + repairs (emitter.py: source-order splicing onto def/class stub lines, bases recovery, @decorator restore, global decls, cond chains, ternaries, nested if/else, loop ranges, break/continue recovery, indent + suite-guard passes)
10. equivalence verify, 3 sweeps (verifier.py: recompile revived source, compare opcode structure, repair, repeat x3)

layout

pyc_revive/
  finder.py  pymagic.py  loader.py  pycdas_parser.py  shim.py
  bytecode.py  normalizer.py  segmenter.py  translator.py  cfg.py
  emitter.py  verifier.py  reconstructor.py  cli.py  __main__.py
  pycdas.exe  README.md  requirements.txt

known limits

• inline comprehensions/genexps render as func(...) placeholders.
• try bodies that fall through into always-run handlers keep flat order instead of guarded flow.
• exotic decorators reduce to bare defs; exotic call shapes degrade to commented disassembly rather than failing.
• pre-3.8 default-argument recovery is best-effort (flag-style MAKE from 3.8+ recovers exactly).
• verifier scores dip across versions: opcode sets drift between releases, so cross-version similarity reads lower than same-version.