What is the best OCLC API for getting the bibliographic information for a given OCLC number? I'd like to get the data in either MARC, MARCXML, or JSON formats. Similarly, given a DOI, is there a way to use an OCLC API to determine the title and open access status of an item?

I have a bunch o' OCLC numbers, and I'd like to get the bibliographics of an item and update a local MARC record. I also have a bunch o' DOIs, and I'd like to learn how many other libraries have the given titles.

I think various OCLC (WorldCat) APIs can be of assistance here, but I'm don't know which one(s). Nor do I know of a (Python) client that I can use as an interface. BookOps-Worldcat? [1] 

Curious minds would like to know.

[1] BookOps-Worldcat - https://bookops-cat.github.io/bookops-worldcat/0.5/

--
Eric Morgan
University of Notre Dame