Eh—I had to do it recently. There was a file format that I was dealing with that was basically a combination of CSV for data and Yaml for headers (and some othe

Eh—I had to do it recently. There was a file format that I was dealing with that was basically a combination of CSV for data and Yaml for headers (and some other edge case stuff) and the Python CSV reader couldn't handle some edge case that we needed handling, mostly around reporting back to the file provider where they messed up one thing or another in the file. It didn't really take me that long. Lots of easy to write tests and the thing is processing a ton of data now for a well known stock exchange. Far easier than, say, the machine learning stuff I've written.