PyCon UK 2019

Mutability for good not evil
2019-09-15, 11:30–12:00, Ferrier Hall

Mutability is a common GOTCHA for new pythonistas. So where is it a good idea to use mutability? And more importantly where is it a bad idea?


Often defined as a bug, mutability is a powerful feature of Python that frequently trips people up. Most tend to avoid it for the weird behaviour it can create and for good reason. But there may be ways in which it can prove vitally useful.

Let's see if we can make use of mutability as a tool to create features instead of bugs.

This talk will first focus on the nature of mutability before moving on to common ways it trips people up. It will then discuss some bad ways it can be used before moving on to possible positive uses of mutability.

I expect to be disagreed with.


Is your proposal suitable for beginners? – False