Simon Willison’s Weblog

My @covidsewage bot now includes useful alt text. I've been running a @covidsewage Mastodon bot for a while now, posting daily screenshots (taken with shot-scraper) of the Santa Clara County COVID in wastewater dashboard.

Prior to today the screenshot was accompanied by the decidedly unhelpful alt text "Screenshot of the latest Covid charts".

I finally fixed that today, closing issue #2 more than two years after I first opened it.

The screenshot is of a Microsoft Power BI dashboard. I hoped I could scrape the key information out of it using JavaScript, but the weirdness of their DOM proved insurmountable.

Instead, I'm using GPT-4o - specifically, this Python code (run using a python -c block in the GitHub Actions YAML file):

import base64, openai
client = openai.OpenAI()
with open('/tmp/covid.png', 'rb') as image_file:
    encoded_image = base64.b64encode(image_file.read()).decode('utf-8')
messages = [
    {'role': 'system',
     'content': 'Return the concentration levels in the sewersheds - single paragraph, no markdown'},
    {'role': 'user', 'content': [
        {'type': 'image_url', 'image_url': {
            'url': 'data:image/png;base64,' + encoded_image
        }}
    ]}
]
completion = client.chat.completions.create(model='gpt-4o', messages=messages)
print(completion.choices[0].message.content)

I'm base64 encoding the screenshot and sending it with this system prompt:

Return the concentration levels in the sewersheds - single paragraph, no markdown

Given this input image:

Here's the text that comes back:

The concentration levels of SARS-CoV-2 in the sewersheds from collected samples are as follows: San Jose Sewershed has a high concentration, Palo Alto Sewershed has a high concentration, Sunnyvale Sewershed has a high concentration, and Gilroy Sewershed has a medium concentration.

The full implementation can be found in the GitHub Actions workflow, which runs on a schedule at 7am Pacific time every day.

# 25th August 2024, 4:09 pm / shot-scraper, openai, covid19, gpt-4, ai, llms, generative-ai, projects, alt-attribute, accessibility

Fix @covidsewage bot to handle a change to the underlying website. I've been running @covidsewage on Mastodon since February last year tweeting a daily screenshot of the Santa Clara County charts showing Covid levels in wastewater.

A few days ago the county changed their website, breaking the bot. The chart now lives on their new COVID in wastewater page.

It's still a Microsoft Power BI dashboard in an <iframe>, but my initial attempts to scrape it didn't quite work. Eventually I realized that Cloudflare protection was blocking my attempts to access the page, but thankfully sending a Firefox user-agent fixed that problem.

The new recipe I'm using to screenshot the chart involves a delightfully messy nested set of calls to shot-scraper - first using shot-scraper javascript to extract the URL attribute for that <iframe>, then feeding that URL to a separate shot-scraper call to generate the screenshot:

shot-scraper -o /tmp/covid.png $(
  shot-scraper javascript \
    'https://publichealth.santaclaracounty.gov/health-information/health-data/disease-data/covid-19/covid-19-wastewater' \
    'document.querySelector("iframe").src' \
    -b firefox \
    --user-agent 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:128.0) Gecko/20100101 Firefox/128.0' \
    --raw
) --wait 5000 -b firefox --retina

# 18th August 2024, 5:26 pm / projects, covid19, shot-scraper

The Tyranny of Spreadsheets (via) In discussing the notorious Excel incident last year when the UK lost track of 16,000 Covid cases due to a .xls row limit, Tim Harford presents a history of the spreadsheet, dating all the way back to Francesco di Marco Datini and double-entry bookkeeping in 1396. A delightful piece of writing.

# 23rd July 2021, 3:57 am / spreadsheets, covid19, history

CoronaFaceImpact (via) Variable fonts are fonts that can be customized by passing in additional parameters, which is done in CSS using the font-variation-settings property. Here’s a ​variable font that shows multiple effects of Covid-19 lockdown on a bearded face, created by Friedrich Althausen.

# 15th November 2020, 10:41 pm / css, fonts, covid19, typography

sba-loans-covid-19-datasette (via) The treasury department released a bunch of data on the Covid-19 SBA Paycheck Protection Program Loan recipients today—I’ve loaded the most interesting data (the $150,000+ loans) into a Datasette instance.

# 7th July 2020, 2:42 am / projects, covid19, data-journalism, datasette

Bill Gates’s vision for life beyond the coronavirus. Fascinating interview with Bill Gates—the most interesting and informative article I’ve read about Covid-19 in quite a while.

# 28th April 2020, 1:01 am / covid19, bill-gates

Estimating COVID-19’s Rt in Real-Time. I’m not qualified to comment on the mathematical approach, but this is a really nice example of a Jupyter Notebook explanatory essay by Kevin Systrom.

# 20th April 2020, 3:06 pm / jupyter, covid19