Looks good. Some minor comments:
- Some cleanups required with spaces around operators (autopep8 does not sort them out) and around line breaks.
- I have some concerns that there are many examples in the examples/ directory but I have no idea if they work and there are 3 test files in there using old style tests. That looks strange.
- I would like some fixups in the tests that do try/except/else. Some of them should be rewritten to be use assertRaises (which would make the tests significantly more readable) and some of them shouldn't be in try blocks at all as they should never raise an exception.