Self-contained code examples

[robmoss]

Originally suggested here by @michaelplanknz.

It would be useful to have a few examples of code that are small, self-contained, and do some simple task. For example, a function that reads in a long-form CSV data set and returns some aggregated values, e.g., number of occurrences of X on each day between Y and Z.

This could serve as an exemplar for how to structure good code (comments, good variable naming, no magic numbers, well defined function inputs/outputs, etc).

It could also include an example of a test function, as I think the idea of automated tests may be a new concept for many (me included!).

Ideally, keeping the tasks relatively simple will mean that code doesn't need to use too many language-specific features or packages but can illustrate principles in a language-agnostic way.