py-cdec

Strong best-effort Python .pyc, marshal, and source analyzer/decompiler.

---

Overview

py-cdec is a Python tool designed to analyze and decompile Python bytecode (.pyc) files and marshal payloads into readable Python-like source code.

It uses heuristic-based reconstruction techniques to recover structure, functions, and readable output from compiled Python artifacts.

This tool is useful for:

• Reverse engineering Python bytecode
• Learning how Python compilers structure code
• Inspecting unknown .pyc files
• Debugging compiled Python modules
• Educational analysis of Python internals

---

Features

• Automatic detection of .py and .pyc files
• Bytecode disassembly support
• Marshal payload extraction and inspection
• Heuristic-based source reconstruction
• Recursive code object analysis
• CLI interface for quick usage
• Lightweight and dependency-free design

---

Installation

Install via pip:

pip install py-cdec

Or install locally:

git clone https://github.com/Gisnsl/py-cdec.git
cd py-cdec
pip install .

---

Usage (Python API)

You can use py-cdec directly inside your Python code.

from pathlib import Path
from py_cdec import PycDecompiler

# Automatically handles both .pyc and .py files
pyc_path = Path("myfile.pyc")  # or myfile.py

decompiler = PycDecompiler(pyc_path)

# Print the decompiled source code directly
print(decompiler)

---

Usage (CLI)

Run directly from terminal:

py-cdec sample.pyc

---

Show Disassembly

To view Python bytecode instructions:

py-cdec sample.pyc --show-dis

---

How It Works

py-cdec internally performs several steps:

1. File Detection

   • Detects whether the input is .py or .pyc

2. Header Parsing

   • Reads Python bytecode headers safely depending on version

3. Marshal Loading

   • Extracts compiled code objects using Python's marshal module

4. Disassembly

   • Converts bytecode into readable instructions

5. Reconstruction

   • Attempts to rebuild Python-like source using heuristics

6. Output Formatting

   • Produces readable structured output

---

Project Goals

The main goal of py-cdec is not perfect decompilation, but:

• Producing readable reconstructed code
• Helping developers understand compiled Python internals
• Providing a safe inspection tool for bytecode analysis

---

Security Notice

âڑ ï¸ڈ WARNING:

Never execute unknown .pyc or marshal payloads directly.

They may contain malicious code even if they appear safe.

Always inspect before execution.

---

Telegram Contact

Developer: @maho_s9

---

License

MIT License