I need to convert any html entity into its ASCII equivalent using Python. My use case is that I am cleaning up some HTML used to build emails to create plaintext emails from the HTML. 
Right now, I only really know how to create unicode from these entities when I need ASCII (I think) so that the plaintext email reads correctly with things like accented characters. I think a basic example is the html entity "& aacute;" or á being encoded into ASCII.
Furthermore, I'm not even 100% sure that ASCII is what I need for a plaintext email. As you can tell, I'm completely lost on this encoding stuff.
ASCII is the American Standard Code for Information Interchange and does not include any accented letters. Your best bet is to get Unicode (as you say you can) and encode it as UTF-8 (maybe ISO-8859-1 or some weird codepage if you're dealing with seriously badly coded user-agents/clients, sigh) -- the content type header of that part together with text/plain can express what encoding you've chosen to use (I do recommend trying UTF-8 unless you have positively demonstrated it cannot work -- it's almost universally supported these days and MUCH more flexible than any ISO-8859 or "codepage" hack!).
Convert html entities to ascii in Python