Simon Willison’s Weblog

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

interactive-feed (via) Sam Morris maintains this project which gathers interactive, graphic and data visualization stories from various newsrooms around the world and publishes them on Twitter, Mastodon and Bluesky.

It runs automatically using GitHub Actions, and gathers data using a number of different techniques - XML feeds, custom API integrations (for the NYT, Guardian and Washington Post) and in some cases by scraping index pages on news websites using CSS selectors and cheerio.

The data it collects is archived as JSON in the data/ directory of the repository.

# 5th July 2024, 11:39 pm / git-scraping, data-journalism, bluesky, mastodon

Figure out who’s leaving the company: dump, diff, repeat (via) Rachel Kroll describes a neat hack for companies with an internal LDAP server or similar machine-readable employee directory: run a cron somewhere internal that grabs the latest version and diffs it against the previous to figure out who has joined or left the company.

I suggest using Git for this—a form of Git scraping—as then you get a detailed commit log of changes over time effectively for free.

I really enjoyed Rachel’s closing thought: “Incidentally, if someone gets mad about you running this sort of thing, you probably don’t want to work there anyway. On the other hand, if you’re able to build such tools without IT or similar getting ”threatened“ by it, then you might be somewhere that actually enjoys creating interesting and useful stuff. Treasure such places. They don’t tend to last.”

# 9th February 2024, 5:44 am / git-scraping, git

Half Moon Bay Pumpkin Festival traffic on Saturday 15th October 2022 (via) It’s the Half Moon Bay Pumpkin Festival this weekend... and its impact on the traffic between our little town of El Granada and Half Moon Bay—8 minutes drive away—is notorious. So I built a git scraper that archives estimated driving times from the Google Maps Navigation API, and used git-history to turn that scraped data into a SQLite database and visualize it on a chart.

# 16th October 2022, 3:56 am / projects, git-scraping, git-history, half-moon-bay

Flat Data. New project from the GitHub OCTO (the Office of the CTO, love that backronym) somewhat inspired by my work on Git scraping: I’m really excited to see GitHub embracing git for CSV/JSON data in this way. Flat incorporates a reusable Action for scraping and storing data (using Deno), a VS Code extension for setting up those workflows and a very nicely designed Flat Viewer web app for browsing CSV and JSON data hosted on GitHub.

# 19th May 2021, 1:05 am / git-scraping, github, deno

nyt-2020-election-scraper. Brilliant application of git scraping by Alex Gaynor and a growing team of contributors. Takes a JSON snapshot of the NYT’s latest election poll figures every five minutes, then runs a Python script to iterate through the history and build an HTML page showing the trends, including what percentage of the remaining votes each candidate needs to win each state. This is the perfect case study in why it can be useful to take a “snapshot if the world right now” data source and turn it into a git revision history over time.

# 6th November 2020, 2:24 pm / elections, alex-gaynor, git-scraping, data-journalism, git, new-york-times

Datasette Weekly: Datasette 0.50, git scraping, extracting columns (via) The first edition of the new Datasette Weekly newsletter—covering Datasette 0.50, Git scraping, extracting columns with sqlite-utils and featuring datasette-graphql as the first “plugin of the week”

# 10th October 2020, 9 pm / sqlite, datasette, projects, graphql, email, sqlite-utils, git-scraping