Python Packaging Skill

Guide for packaging Python applications into professional executable files (.exe, .app) using PyInstaller.

📦 PyInstaller Basics

Installation

pip install pyinstaller

Basic Commands

🪟 Windows Packaging

Standard Command for GUI App

python -m PyInstaller --onefile --noconsole --name "MyApp" main.py

Standard Command for Console Tool

python -m PyInstaller --onefile --name "MyTool" main.py

⚠️ Windows Notes

• Windows Defender might report False Positive with --onefile. Use --onedir if avoiding this is priority.
• Icon must be .ico file.

🍎 macOS Packaging

Standard Command

python -m PyInstaller --windowed --noconsole --name "MyApp" main.py

⚠️ macOS Notes

• Does not support --onefile very well (slow startup). Recommend default (--onedir) or --windowed.
• Result is .app bundle, not a single file.
• Needs code signing if running on other machines to avoid Security blocks (advanced).

🛠️ Handling Assets (Images, Configs)

When packaging with --onefile, assets are unpacked to a temp folder _MEIxxxx. Code is needed to find the correct path:

Pattern: Resource Path

import sys
import os

def resource_path(relative_path):
    """ Get absolute path to resource, works for dev and for PyInstaller """
    try:
        # PyInstaller creates a temp folder and stores path in _MEIPASS
        base_path = sys._MEIPASS
    except Exception:
        base_path = os.path.abspath(".")

    return os.path.join(base_path, relative_path)

# Usage
icon_path = resource_path("icon.png")

Adding assets to build

Use --add-data flag:

• Windows: --add-data "src;dest"
• macOS/Linux: --add-data "src:dest"

Example:

# Windows
pyinstaller --onefile --add-data "config.json;." main.py

📄 requirements.txt Best Practices

Always optimize requirements.txt before building to reduce exe size.

Do NOT:

pip freeze > requirements.txt (Captures all system junk libraries)

DO:

List only actually used libraries:

PyQt6>=6.4.0
pandas
openpyxl
pillow

🤖 Cross-Platform Rules

PyInstaller is NOT a Cross-Compiler.

• Want .exe file -> Must build on Windows.
• Want .app file -> Must build on macOS.

Solutions:

1. Use CI/CD (GitHub Actions) to build both.
2. Or setup Virtual Machine (VM) to build.

✅ Packaging Checklist

• Run pip install -r requirements.txt first
• Test app runs okay with python main.py
• Handle asset paths (resource_path)
• Run correct build command for OS
• Test output file in dist/ directory
• Check virus scan (for Windows)

🤖 Agentic Protocol

Skill Metadata

• Version: 1.0.0
• Last Updated: 2026-01-27

1. Activation Log

When activating this skill, print: "🎯 [SKILL ACTIVATED] python-packaging v1.0.0" "📋 Parameters:" " - Target: [script.py]" " - Mode: [onefile|onedir]" " - OS: [Windows|macOS]" " - Assets: [listofincluded_assets]"

2. User Confirmation

Before running the build command (long process): "I'm about to package [Target] using PyInstaller with options: [Options]. This may take a few minutes. Proceed?"

3. Completion Log

• Success: "✅ [python-packaging] Build complete. Artifact: dist/[filename]"
• Error: "❌ [python-packaging] Build failed. Check logs."