Download multiple CSVs using Flask?

Question

I have an app that takes in some information, performs some calculations using pandas, and turns the final pandas data frame into a CSV that is then downloaded using the Fla

Answer 1

You could return a MIME Multipart response, a zip file, or a TAR ball (please note the linked RFC is somewhat out of date, but is easier to quickly get up to speed with because it's in HTML; the official one is here).

If you choose to do a MIME multipart response, a good starting point might be to look at the MultipartEncoder and MultipartDecoder in requests toolbelt; you may be able to use them directly, or at least subclass/compose using those to get your desired behavior. Zip files and TAR balls can be implemented using standard library modules.

An alternative would be to design your API so that you were returning JSON, use a header (or XML element or JSON field) to indicate that additional CSVs could be obtained by another request, or similar.