Add .gitignore for Python project

Ignore Python cache files, virtual environments, IDE files, and other
generated artifacts to keep the repository clean.

Includes patterns for:
- __pycache__/ and *.pyc files
- Virtual environments (venv/, env/, .venv)
- IDE files (.vscode/, .idea/)
- OS files (.DS_Store, Thumbs.db)
- Jupyter checkpoints
- Testing artifacts

Author: claude

.gitignore

@@ -0,0 +1,50 @@
+# Python
+__pycache__/
+*.py[cod]
+*$py.class
+*.so
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+pip-wheel-metadata/
+share/python-wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# Virtual environments
+venv/
+ENV/
+env/
+.venv
+
+# IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Jupyter
+.ipynb_checkpoints/
+*.ipynb_checkpoints
+
+# Testing
+.pytest_cache/
+.coverage
+htmlcov/