Simon Willison’s Weblog

Generating Descriptive Weather Reports with LLMs. Drew Breunig produces the first example I've seen in the wild of the new LLM attachments Python API. Drew's Downtown San Francisco Weather Vibes project combines output from a JSON weather API with the latest image from a webcam pointed at downtown San Francisco to produce a weather report "with a style somewhere between Jack Kerouac and J. Peterman".

Here's the Python code that constructs and executes the prompt. The code runs in GitHub Actions.

# 29th October 2024, 11:12 pm / vision-llms, drew-breunig, llm, generative-ai, ai, llms, github-actions, prompt-engineering

UV with GitHub Actions to run an RSS to README project. Jeff Triplett demonstrates a very neat pattern for using uv to run Python scripts with their dependencies inside of GitHub Actions. First, add uv to the workflow using the setup-uv action:

- uses: astral-sh/setup-uv@v3
  with:
    enable-cache: true
    cache-dependency-glob: "*.py"

This enables the caching feature, which stores uv's own cache of downloads from PyPI between runs. The cache-dependency-glob key ensures that this cache will be invalidated if any .py file in the repository is updated.

Now you can run Python scripts using steps that look like this:

- run: uv run fetch-rss.py

If that Python script begins with some dependency definitions (PEP 723) they will be automatically installed by uv run on the first run and reused from the cache in the future. From the start of fetch-rss.py:

# /// script
# requires-python = ">=3.11"
# dependencies = [
#     "feedparser",
#     "typer",
# ]
# ///

uv will download the required Python version and cache that as well.

# 5th October 2024, 11:39 pm / uv, jeff-triplett, github-actions, python

New improved commit messages for scrape-hacker-news-by-domain. My simonw/scrape-hacker-news-by-domain repo has a very specific purpose. Once an hour it scrapes the Hacker News /from?site=simonwillison.net page (and the equivalent for datasette.io) using my shot-scraper tool and stashes the parsed links, scores and comment counts in JSON files in that repo.

It does this mainly so I can subscribe to GitHub's Atom feed of the commit log - visit simonw/scrape-hacker-news-by-domain/commits/main and add .atom to the URL to get that.

NetNewsWire will inform me within about an hour if any of my content has made it to Hacker News, and the repo will track the score and comment count for me over time. I wrote more about how this works in Scraping web pages from the command line with shot-scraper back in March 2022.

Prior to the latest improvement, the commit messages themselves were pretty uninformative. The message had the date, and to actually see which Hacker News post it was referring to, I had to click through to the commit and look at the diff.

I built my csv-diff tool a while back to help address this problem: it can produce a slightly more human-readable version of a diff between two CSV or JSON files, ideally suited for including in a commit message attached to a git scraping repo like this one.

I got that working, but there was still room for improvement. I recently learned that any Hacker News thread has an undocumented URL at /latest?id=x which displays the most recently added comments at the top.

I wanted that in my commit messages, so I could quickly click a link to see the most recent comments on a thread.

So... I added one more feature to csv-diff: a new --extra option lets you specify a Python format string to be used to add extra fields to the displayed difference.

My GitHub Actions workflow now runs this command:

csv-diff simonwillison-net.json simonwillison-net-new.json \
  --key id --format json \
  --extra latest 'https://news.ycombinator.com/latest?id={id}' \
  >> /tmp/commit.txt

This generates the diff between the two versions, using the id property in the JSON to tie records together. It adds a latest field linking to that URL.

The commits now look like this:

# 6th September 2024, 5:40 am / shot-scraper, github-actions, projects, hacker-news, git-scraping, json

GitHub Actions: Faster Python runs with cached virtual environments (via) Adam Johnson shares his improved pattern for caching Python environments in GitHub Actions.

I've been using the pattern where you add cache: pip to the actions/setup-python block, but it has two disadvantages: if the tests fail the cache won't be saved at the end, and it still spends time installing the packages despite not needing to download them fresh since the wheels are in the cache.

Adam's pattern works differently: he caches the entire .venv/ folder between runs, avoiding the overhead of installing all of those packages. He also wraps the block that installs the packages between explicit actions/cache/restore and actions/cache/save steps to avoid the case where failed tests skip the cache persistence.

# 19th July 2024, 2:14 pm / adam-johnson, github-actions, python

qrank (via) Interesting and very niche project by Colin Dellow.

Wikidata has pages for huge numbers of concepts, people, places and things.

One of the many pieces of data they publish is QRank—“ranking Wikidata entities by aggregating page views on Wikipedia, Wikispecies, Wikibooks, Wikiquote, and other Wikimedia projects”. Every item gets a score and these scores can be used to answer questions like “which island nations get the most interest across Wikipedia”—potentially useful for things like deciding which labels to display on a highly compressed map of the world.

QRank is published as a gzipped CSV file.

Colin’s hikeratlas/qrank GitHub repository runs weekly, fetches the latest qrank.csv.gz file and loads it into a SQLite database using SQLite’s “.import” mechanism. Then it publishes the resulting SQLite database as an asset attached to the “latest” GitHub release on that repo—currently a 307MB file.

The database itself has just a single table mapping the Wikidata ID (a primary key integer) to the latest QRank—another integer. You’d need your own set of data with Wikidata IDs to join against this to do anything useful.

I’d never thought of using GitHub Releases for this kind of thing. I think it’s a really interesting pattern.

# 21st April 2024, 10:28 pm / wikipedia, github-actions, sqlite, colin-dellow

GitHub Actions: Introducing the new M1 macOS runner available to open source! Set “runs-on: macos-14” to run a GitHub Actions workflow on a 7GB of RAM ARM M1 runner. I have been looking forward to this for ages: it should make it much easier to build releases of both Electron apps and Python binary wheels for Apple Silicon.

# 31st January 2024, 2:04 am / github-actions, macosx

Leveraging ’shot-scraper’ and creating image diffs. Üllar Seerme has a neat recipe for using shot-scraper and ImageMagick to create differential animations showing how a scraped web page has visually changed.

# 24th October 2022, 9:34 pm / imagemagick, shot-scraper, github-actions

How to create a Python package in 2022 (via) Fantastic tutorial on modern Python packaging by Rodrigo Girão Serrão. I’ve been meaning to figure out Poetry for a while now and this gave me exactly the information I needed to start figuring it out. Great coverage of GitHub Actions, Tox and pre-commit as well.

# 15th October 2022, 10:10 pm / packaging, python, github-actions

upptime (via) “Open-source uptime monitor and status page, powered entirely by GitHub Actions, Issues, and Pages.” This is a very creative (ab)use of GitHub Actions: it runs a scheduled action to check the availability of sites that you specify, records the results in a YAML file (with the commit history tracking them over time) and can automatically open a GitHub issue for you if it detects a new incident.

# 26th May 2022, 3:53 am / github-actions

simonw/datasette-screenshots (via) I started a new GitHub repository to automate taking screenshots of Datasette for marketing purposes, using my shot-scraper browser automation tool.

# 17th May 2022, 5:56 pm / projects, shot-scraper, github-actions, datasette

Supercharging GitHub Actions with Job Summaries (via) GitHub Actions workflows can now generate a rendered Markdown summary of, well, anything that you can think to generate as part of the workflow execution. I particularly like the way this is designed: they provide a filename in a $GITHUB_STEP_SUMMARY environment variable which you can then append data to from each of your steps.

# 16th May 2022, 11:02 pm / github-actions

@newshomepages (via) Ben Welsh used my shot-scraper tool and GitHub Actions to launch a Twitter bot which tweets screenshots of newspaper homepages on a scheduled basis. Ben says: “The tech is so easy, I was able to pull it off in a couple hours at zero cost. A decade ago I ran a similar project using the cloud resources of the day. [...] It costs thousands of dollars and the screenshots were of much lower quality. Incredible progress!”

# 12th March 2022, 7:21 pm / twitter, shot-scraper, github-actions, playwright, ben-welsh

wheel.yml for Pyjion using cibuildwheel (via) cibuildwheel, maintained by the Python Packaging Authority, builds and tests Python wheels across multiple platforms. I hadn’t realized quite how minimal a configuration using their GitHub Actions action was until I looked at how Pyjion was using it.

# 10th December 2021, 3:05 am / github-actions, python