Hmm, I see; I did not know that.

I had just assumed that `./python -m test test_*` was the standard command for running tests.

However, if one does run tests using standalone `datetimetester` (which only imports the _Fast C extension module), then I'll have to rewrite some of the self.skipTest conditions such that they are more defensive, i.e.:

    if '_Pure' not in self.__class__.__name__:
         self.skipTest('...')

instead of:

    if '_Fast' in self.__class__.__name__:
         self.skipTest('...')


because some (one?) of the tests fail otherwise.

Shall I make that change?

Also, here is an alternate fix which is a tiny bit less murky than straight up de-duplication of test-classes: https://github.com/musically-ut/cpython/pull/1/files

I'm not sure whether this is any clearer or less fragile, though.

~
ut