Project structure opinions when cleaning messy data?

Hi all!

I recently started a personal project looking at British box office data from these datasets.

I'm just finishing up the whole data importing script, and as I was coding I started wondering about how to structure my project and what code belongs where.

The spreadsheets are fairly poorly formatted since they're meant to be viewed in excel, so I've had to do a fair bit of manipulating the data to get it consistent (I've come across literally half a dozen encodings for no change in %age change in gross revenue lol). But I was wondering if there's much of a line between cleaning data as you import it vs munging data after you have it.

Here's the script where I actually import and manipulate the spreadsheets for the curious. (At time of writing, there are still a few bits to add!)

I was just wondering if there are strong feelings about what's appropriate for the data folder vs the munge folder in ProjectTemplate, maybe a good jumping off point for discussion (maybe not something anyone has really cared to consider before lol)