Python

Python is central to countless development workflows, and Kloud Workspace ships with a finely‑tuned Python toolchain to keep you productive.

Key features provided out‑of‑the‑box:

• Python 3.11 runtime, ready for immediate use.
• Both pip and the lightning‑fast uv package manager.
• Automatic virtual environment activation when navigating into project directories.
• Opinionated linting & formatting with ruff its IDE extension.
• Language‑intelligence powered by Meta's Pyrefly language server — Rust‑based, type‑aware, fast.
• Pre‑generated IPython (itself, not pre‑installed) profile that matches the Kloud Workspace color palette.

Package Management with uv

For day‑to‑day dependency work, we recommend uv, which offers:

• Near instant dependency resolution.
• Deterministic, lock‑file–friendly installs.
• Seamless compatibility with requirements.txt and pyproject.toml.

Additional Packages & Tools

Upon workspace startup, Kloud Workspace evaluates two environment variables to automatically install user-defined Python packages and CLI tools:

• WS_PIP_ADDITIONAL_PACKAGES: Additional global Python packages installed during startup.
• WS_UV_ADDITIONAL_TOOLS: Additional global Python CLI tools installed during startup.

Both accept a space-delimited list. Reach for pip to install importable libraries into the user site and uv to install global CLI tools.

docker run \
  -e WS_PIP_ADDITIONAL_PACKAGES="httpx==0.27.0 rich" \
  -e WS_UV_ADDITIONAL_TOOLS="ruff poetry==1.8.0" \
  ghcr.io/kloudkit/workspace:v0.4.0

Automatic venv Activation

Kloud Workspace includes an auto-venv plugin that automatically activates Python virtual environments when you navigate into a project directory.

When you cd into a directory containing a .venv or venv folder, the virtual environment is activated automatically.

When you leave the project directory, it deactivates.

This works seamlessly with uv venv or python -m venv:

Linting & Formatting with ruff

Kloud Workspace bundles Ruff and its VS Code extension for real‑time feedback. Our default configuration is deep and opinionated:

• Custom caching and line formatting behavior.
• Auto-fixing capabilities enabled by default.
• Fine-tuned rules for indentation width and maximum line length.
• Targeting Python 3.11 for compatibility alignment.
• A carefully selected ruleset that includes and excludes specific error codes from multiple linting plugins.
• Context-aware formatting such as consistent line endings and formatting of docstring code.
• Special rules for import sorting and type-checking blocks.
• Per-file rule overrides to reduce noise in test directories.

Configuration Lookup

Kloud Workspace ships with a default Ruff configuration at ~/.config/ruff/ruff.toml that suits most projects. If you need custom linting rules, add a ruff.toml file at your project’s root.

You can also copy the default configuration with:

ws-cli template apply ruff

For more details, refer to the ws-cli documentation.

Language Server

Kloud Workspace ships Meta's Pyrefly as the Python language server — Rust‑based, type‑aware, and dramatically faster than alternatives. Strict type checking is on by default and honors the standard configuration knobs.

If you prefer a lighter‑weight LSP, override the editor settings via WS_EDITOR_SETTINGS_MERGE to disable python.pyrefly.* and select your preferred language server.

Optional Interactive Shell

For an enhanced REPL experience you can install IPython:

pip install ipython
# or: uv pip install ipython

Kloud Workspace already includes a custom IPython profile (/etc/ipython/ipython_config) whose prompt colors and syntax‑highlighting align with the Kloud Workspace's overall theme.

Once IPython is installed it will pick up these settings automatically, no additional configuration required.