I won the pictured Android figurine in a computer science trivia contest.

I have been happily using Python for a variety of purposes since version 2.5. As a result, my Python workflow is very important to me. When I first heard about uv, I was skeptical that it would actually be a drop-in replacement for pip (and friends) for me. I decided to spend January 2025 giving it a genuine try and I am so very glad I did. For me, uv totally lives up to the hype!

⭐️✨ I think uv makes Python easier — and more fun! ✨⭐️

🌞 What is uv?

In short, uv is an extremely fast Python package manager, written in Rust.

❓ Why uv?

Do you use Python and virtual environments? Do you find them kinda annoying and cumbersome?

👉 Try uv. 👈

There are other good reasons to use uv but that’s my elevator pitch. In this post, I want to walk through a few examples of how I am using uv to help illustrate why I am so excited about it. Grab your copy and follow along!

🗺️ How I am using uv

To get a Python console:

uv run python3

Spin up a Web server serving your local directory:

uv run python -m http.server
uv run python -m http.server 8888

📝 requirements.txt

Do you find yourself doing something like this?

python3 -m venv v
source v/bin/activate
pip install -r requirements.txt

There is support using pip install with uv. Those three lines above turn into one:

uv pip install -r requirements.txt

You don’t have to create or activate the virtual environment first (but you can if you would like).

Whether or not you will actually need to do this will depend a bit on what you are trying to achieve. There’s more about how uv handles dependencies below.

🧰 Using tools

You can use uvx to run Python packages that can be used as tools. Let’s say you wanted to use Waybackpy to save a page in the Wayback Machine. When you run uvx (an alias for uv tool run), you bypass the pip install step. This command will take care of installing and running the tool all in one go.

uv tool run waybackpy --url https://brie.dev --save

Let’s say you wanted to use the pastebin-bisque tool I maintain to download some files from Pastebin:

uvx pastebin-bisque -u thecutestcat

For some tools, the package name and the tool name don’t match. You’ll need --from for those situations.

uv tool run --from mitmproxy mitmweb

uvx   --from norwegianblue  eol  --md   gitlab   | head -n5
| cycle |  release   | latest   | latest release |  support   |    eol     |
| :-----| :--------: | :--------| :------------: | :--------: | :--------: |
| 17.8  | 2025-01-16 | 17.8.1 |   2025-01-22   | 2025-02-20 | 2025-04-17 |
| 17.7  | 2024-12-19 | 17.7.3 |   2025-01-22   | 2025-01-16 | 2025-03-20 |
| 17.6  | 2024-11-21 | 17.6.4 |   2025-01-22   | 2024-12-19 | 2025-02-20 |

📜 Running scripts

Running scripts with uv is as simple as:

uv run python whatever.py

If the whatever.py script has dependencies, you’d run it with something like this:

uv run --with datetime,requests python whatever.py

The list of dependencies can get a bit unwieldy. Instead of using --with, you can inline the dependencies!

🛼 Inlining dependencies

This is not a feature in uv but it makes using uv so much nicer if you’re already taking advantage of this Python functionality. Without it, you would have to run something like this:

uv run --with argparse,datetime,passgen,faker,requests python main.py 4 

With it, you would just run:

uv run python main.py 4

Rob Allen has a great blog post on how to do this.

📍 Getting a specific version of Python

With --python, you can request a specific version of Python.

# uv run --python 3.12 python -V
Python 3.12.8

That command tells uv to use Python 3.12 when running python -V to print the version of Python that is in use. Most uv commands support this flag.

📦 Publishing Python Packages with uv

In fall 2023, I wrote about building my toolbox for publishing Python packages to PyPI and GitLab Package Registry. I have been able to replace the majority of it with uv. (I include a separate tool for version bumping and that’s fine.)

📚 Additional Reading

• ⭐️ The uv docs are great.
• uv under discussion on Mastodon — Simon Willison has collected excerpts from uv chatter on Mastodon.
• UV — I am (somewhat) sold
• Defining Python dependencies at the top of the file

💖 From the Heart

🐍 I haven’t been this excited about something new in the Python space in a very long time. As I get a handle on how I intend to use uv moving forward, I’ll work on building aliases and helper scripts to make my usage of uv even more efficient.

🐈‍⬛ Be well!