Create and activate a virtual environment
Keeps this project’s packages separate from the system.
python3 -m venv .venv && source .venv/bin/activatePython, pip & uv commands
Create virtual environments, install and freeze packages with pip, and use uv, the fast modern Python package manager.
11 commands
Create and activate a venv on Windows
If activation is blocked, run: Set-ExecutionPolicy -Scope CurrentUser RemoteSigned
python -m venv .venv; .venv\Scripts\Activate.ps1Install from requirements.txt
Installs every package listed.
pip install -r requirements.txtSave installed packages
Writes exact versions of everything in the environment.
pip freeze > requirements.txtUpgrade pip
Use python instead of python3 on Windows.
python3 -m pip install --upgrade pipInstall uv
uv is a very fast Python package and project manager.
curl -LsSf https://astral.sh/uv/install.sh | shPipes a script from the internet into your shell. This is the official installer; read it first if unsure.
Start a project with uv
Creates pyproject.toml, a starter main.py and a .gitignore.
uv init && cd Add a package with uv
Installs it into the project environment and records it in pyproject.toml.
uv add Run a script with uv
Runs inside the project environment, syncing dependencies first.
uv run Pretty-print JSON
Formats a JSON file with indentation. Also works on piped input.
python3 -m json.tool Which Python am I using?
Path and version of the active interpreter.
which python3 && python3 --versionEvery command copies as plain, clean text: no curly quotes, no long dashes, no invisible characters.