Setting Up Python Projects

New projects start with the full safety net configured. Templates are in the repo: https://github.com/quick-brown-foxxx/coding_rules_python/tree/master/templates`.

Make sure to read repo's readme.

Project Layout

project/
├── src/appname/
│   ├── __init__.py           # __version__ = "0.1.0"
│   ├── __main__.py           # Entry point
│   ├── constants.py          # Shared constants
│   ├── core/                 # Business logic
│   │   ├── models.py         # Data types (dataclasses)
│   │   ├── manager.py        # Business operations
│   │   └── exceptions.py     # Custom exception hierarchy
│   ├── cli/                  # CLI interface
│   │   ├── commands.py       # Command implementations
│   │   ├── parser.py         # Argument parsing
│   │   └── output.py         # Formatted output helpers
│   ├── ui/                   # Qt GUI (if applicable)
│   │   ├── main_window.py
│   │   ├── dialogs/
│   │   └── widgets/
│   ├── utils/                # Stateless utilities
│   │   ├── paths.py
│   │   └── logging.py
│   ├── wrappers/             # Third-party lib wrappers
│   │   └── some_wrapper.py
│   └── stubs/                # Type stubs for untyped libs
├── tests/
│   ├── unit/
│   ├── integration/
│   ├── fixtures/
│   └── conftest.py
├── scripts/                  # Dev utilities
│   ├── bootstrap.py          # Setup script
│   └── check_type_ignore.py
├── docs/
│   ├── coding_rules.md       # Copy from rules/coding_rules.md
│   └── PHILOSOPHY.md          # Copy from PHILOSOPHY.md
├── shared/                   # Cross-cutting (copy from coding_rules_python/reusable/)
│   ├── logging/              # Logging + colored output (if needed)
│   └── shortcuts/            # Keyboard shortcuts (if PySide6 app)
├── AGENTS.md                 # Copy from templates/AGENTS.md, customize
├── CLAUDE.md                 # Symlink → AGENTS.md
├── pyproject.toml            # Copy from templates/pyproject.toml, customize
├── .pre-commit-config.yaml   # Copy from templates/pre-commit-config.yaml
├── .gitignore                # Copy from templates/gitignore
└── .vscode/
    ├── settings.json         # Copy from templates/vscode_settings.json
    └── extensions.json       # Copy from templates/vscode_extensions.json

Setup Checklist

1. Create directory structure:

   mkdir -p src/APPNAME tests/unit tests/integration tests/fixtures scripts docs .vscode
   

2. Copy template and reference files:

   • templates/pyproject.toml → pyproject.toml (update [project] section)
   • templates/AGENTS.md → AGENTS.md (fill TODO sections)
   • templates/pre-commit-config.yaml → .pre-commit-config.yaml
   • templates/gitignore → .gitignore
   • templates/vscode_settings.json → .vscode/settings.json
   • templates/vscode_extensions.json → .vscode/extensions.json
   • rules/coding_rules.md → docs/coding_rules.md
   • PHILOSOPHY.md → docs/PHILOSOPHY.md
   • Create symlink: ln -s AGENTS.md CLAUDE.md

3. Copy reusable code (if needed):

   • From coding_rules_python/reusable/ copy modules you need into shared/
   • logging/ — colored logging, file rotating logs, CLI output (see setting-up-logging skill)
   • shortcuts/ — keyboard shortcuts for PySide6 apps (see setting-up-shortcuts skill)
   • Also copy matching tests from coding_rules_python/reusable_tests/ into your tests/ (e.g., test_shortcuts_base.py, test_shortcuts_manager.py)
   • Update import paths after copying (reusable. → shared. or your package path, reusable_tests. → your test package)

4. Create entry points:

   # src/APPNAME/__init__.py
   __version__ = "0.1.0"
   
   # src/APPNAME/__main__.py
   import sys
   
   def main() -> int:
       if len(sys.argv) > 1:
           return cli_main()  # CLI mode
       return gui_main()      # GUI mode (if applicable)
   
   if __name__ == "__main__":
       sys.exit(main())
   

5. Create initial test:

   # tests/test_main.py
   from APPNAME.__main__ import main
   
   def test_main_runs(capsys: pytest.CaptureFixture[str]) -> None:
       assert main() == 0
   

6. Initialize environment:

   git init
   uv sync --all-extras --group dev
   uv run pre-commit install
   uv run poe lint_full
   uv run poe test
   

7. Verify everything works:

   • uv run poe app runs the application
   • uv run poe lint_full passes with 0 errors
   • uv run poe test passes

Bootstrap Script

# scripts/bootstrap.py
"""Set up development environment."""
import subprocess

def main() -> None:
    subprocess.run(["uv", "sync", "--all-extras", "--group", "dev"], check=True)
    subprocess.run(["uv", "run", "pre-commit", "install"], check=True)
    print("Development environment ready.")

if __name__ == "__main__":
    main()

Adapt to Tech Stack & Domain

After scaffolding, adapt everything to the specific project. The templates are a starting point, not a straitjacket. docs/PHILOSOPHY.md is the only ruling constant — everything else bends to fit the project's tech stack, domain, and constraints.

What to adapt

Research before building

When setting up a project in an unfamiliar domain or with unfamiliar libraries:

1. Research the domain's conventions — look up how well-maintained projects in the same space are structured
2. Check library compatibility — verify libraries work together and with basedpyright strict mode (some libraries have poor type stubs; plan wrappers early)
3. Identify domain-specific tooling — some domains have their own linters, formatters, or validation tools that complement the base toolchain
4. Check for basedpyright known issues — some libraries (numpy, pandas, SQLAlchemy) need specific configuration or stub packages to work cleanly in strict mode

Quick customization checklist

• Directory layout matches the domain, not the generic template
• Dependencies are domain-appropriate (researched, not guessed)
• AGENTS.md describes this project, not a generic Python project
• coding_rules.md has domain-specific additions if needed
• Test structure reflects what matters most for this project
• basedpyright config accounts for domain-specific library quirks