If I'm writing a library in C that includes a Python interface, is it OK to just write unit tests for the functions, etc in the Python interface? Assuming the Python interface is complete, it should imply the C code works.
Mostly I'm being lazy in that the Python unit test thing takes almost zero effort to use.
thanks,
-nick
I see two mains restrictions to unit testing thru the Python interface. Whether it is OK to testing with those restrictions or not depends on what the library does, how it is implemented, and on the alignment of the Python interface on the interface of the C library.

the library can only be exercised the way the Python library is using it. This is not a problem as far as the Python interface is the only client of the C library.
the Python unit tests do not have access to the internals of the C library as unit tests written in C would have: only what is exposed via the Python interface is reachable. Therefore


if a problem arises after 10 calls to the Python interface, 10 calls will be needed to reproduce it, while a unit test written in C could create the fixture directly, without the 10 calls. This can make Python tests slower.
the Python unit tests couldn't be as isolated as C unit tests could be as they may not been able to reset the internals of the library
trickle down unit tests