In November 2021 I got offered a 30€ discount on the BahnCard25 from the Deutsche Bahn AG. Some time ago I cancelled my BahnCard because I wasn't using it enough to justify having one. With a 30€ discount I should have no problem getting the remaining 25.7€ of value back.

But I wanted to track this. I am using hledger to track all my expenses and assets.

The ledger statement for the Bahncard looks like this:

2021-11-24 BahnCard 25
Expenses:misc:Bahncard                     €25.7
Assets:Checking Account
(worthIt:Bahncard2022)                     €55.7  ; full price
(worthIt:Bahncard2022)                      €-30  ; discount

And one statement of the travels looks like this:

2022-01-04 Travel S->KA
Expenses:Travel:Deutsche Bahn             €10.65
Assets:Checking Account
(worthIt:Bahncard2022)                    -€3.55

Result of my current balance:

hledger reg ^WorthIt:Bahncard2022

I build a crawler to get the waterlevels of rivers in Baden-Württemberg every 15 minutes. There is no real API, but I wanted to plot the data over time. The page is rendered using Javascript which made a beautifulsoup solution not possible.

But there is Playwright for Python.

Playwright works with multiple browsers and supports an interactive mode.

As example for the waterlevel website:

import asyncio
from playwright.async_api import async_playwright

async def main():
    async with async_playwright() as p:
        browser = await p.chromium.launch(headless=False)
        page = await browser.new_page()
        await page.goto("https://www.hvz.baden-wuerttemberg.de/overview.html")
        print(await page.title())
        # pause to inspect the page
        await page.pause()
        await browser.close()

asyncio.run(main())

This starts an interactive chromium. F12 is available and every page.pause() is a breakpoint. The page is paused after printing the title of the website.

The interactivity and full debug capabilities allow a lot easier development than using beautifulsoup on a downloaded HTML file.