Since 2010

How to think about lockdowns

Wednesday 26 August 2020

This video from CGP Grey is gloriously logical and well-reasoned, especially the first 7 minutes. A worthy reminder that (almost) everyone is doing the best they can given the information they have at the time.

Shout out to this quip in response to “How will lockdown affect education in the future?”:

I think this quarantine has made plain some of the necessary lies of civilisation around education, particularly higher education, but, I leave what those are as an exercise for the viewer. For now.


Simple tips for security and serial numbers

Monday 10 August 2020

Seth Godin has some good tips for dealing with random-but-usable-by-humans strings and codes. It’s something I spent a bit of time on when building our wedding website: the codes needed to be mildly secure, but easy to enter.

The final solution, which doesn’t seem to have caused any issues, was a random selection of 6 characters from upper-case A–Z, minus “I” and “O”, plus digits 2–9:

choices = ('A'..'Z').to_a - ['I', 'O'] + ('2'..'9').to_a

When shown to humans, the codes are displayed as two groups of three characters:


But, the codes can be entered with or without the space, and will be accepted whether they’re entered upper-case or not:

Invitation.find_by rsvp_code: params[:rsvp_code].upcase.gsub(/\s/, '')

So the example above could be entered as “a5d8fu”.

I do disagree with Seth’s last comment about saying “please” in forms though. I don’t think this fools anyone - users know they’re looking at a form and not having a conversation with a human. No need to beg.


Monday 6 July 2020

I’ve never been a huge fan of the datetime module in Python, but listening to one of the core developers of Python on “Talk Python” episode 271 has changed that.

I’d encourage anyone who stores dates and times in a database to listen to this. The guy does a really good job of explaining when we should use naive datetimes, aware datetimes, and why simply using UTC and converting as needed isn’t always the right choice.

I love this stuff.