I recently started using get_iplayer again, and was disappointed to find that the category search for TV shows was removed. However, when I download any program in the genre metadata, there is the category. Is there a way to search by this metadata tag?

No.

Category metadata was removed by the BBC from the feeds get_iplayer used to 'index' available programmes and their category.

Category information may be included with each download but short of grabbing every single individual programme and building a list there's not way to get that information 'in advance'.

No. The metadata category can only be retrieved when you have selected a programme for download. You'll have to use the categories on the iPlayer site.

OK, thanks. That's a shame but I'll find a way to work around it.