Mercantile, the module of web mercator XYZ tile utilities that I started at Mapbox, is complete. Version 1.0.0 is on the Python Package Index today and can be obtained using pip: pip install -U mercantile, no --pre option necessary. The latest and greatest documentation is at http://mercantile.readthedocs.io/en/latest/. I expect to be making improvements to the docs over the next few weeks. Please don't be shy about pointing out what the docs lack.
I'm super grateful for the help from Matthew Perry, Patrick M. Young, Amit Kapadia, Damon Burgett, Stefano Costa, Jacob Wasserman, and Brendan Ward. Sam Matthews doesn't appear in the git log, but helped me with the Sphinx layout.
I'm fortunate to be able to work on open source projects at my job and proud of Mapbox's continuing commitment to open source. Virtual confetti is being tossed in Mapbox's main Slack channel this morning and I'm feeling good.