For some time now, Python developers have been able to “annotate” names with type information. With Python 3.5, type hints officially became part of the language (see PEP 484).

He’s using Python which makes the process fairly painless (we’ll get to that in a minute) but the value of his post is in the explanation surrounding how to interpret the data.

Python 3.14 has a new feature called the template string, or t-string, type. A t-string superficially resembles an f-string, but it’s designed to do something very different.