Understanding uv and its key advantages

What is uv?

• uv is an extremely fast, modern Python package and project manager written in Rust, designed as an all-in-one replacement for existing tools like pip, virtualenv, pipx, and pyenv. uv promises dramatic performance gains and a simplified workflow for Python developers.

• It consolidates multiple tools into a single, cohesive command-line interface. pip + venv + pip-tools + pipx — replaced by one fast tool

• It fully supports pyproject.toml for defining project metadata and dependencies, aligning with modern Python packaging standards.

Advantage

1. pyproject.toml as the source of truth

2. A lockfile (uv.lock) for deterministic installs

3. No need to “activate” venv

4. Better dev vs prod dependency separation

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Essential uv commands for project setup

Uv command and workflow

Setup uv and python

• Install uv and update path

curl -Ls https://astral.sh/uv/install.sh | bash

• Verify uv is installed

uv --version uv 0.9.21

• Install multiple python version

uv python install 3.14

• List Python version → uv python list

  • Lists all Python interpreters uv can see (includes system-installed and uv-installed Python)

  • uv separates system Python from project Python, so OS updates can’t silently break your code or CI pipelines.

  • uv python list always shows system-installed Python if no Python is installed via uv, because uv discovers and reuses what the OS already provides.

  • Once you install Python via uv python install, uv prefers that version, but system Python remains visible as a fallback—not replaced.

• Create a file with required python version

echo "3.13" > .python-version cat .python-version >>  3.13

• Initialize python project → uv init

• Optional - Change project description in pyproject.toml

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Creating an API testing project using uv

• Setup python virtual environment → uv venv --python 3.13

• Install packages

uv add requests faker uv add --group test pytest uv add --dev black ruff mypy

• After running above command, it updated pyproject.toml with dependencies and created uv.lock

• List dependency → uv pip list

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Reference

• GitHub - astral-sh/uv: An extremely fast Python package and project manager, written in Rust.

• Installing and managing Python | uv