Karsten W. wrote: > However, I find myself constantly changing the API and I am looking for > a more reliable way > to check my implementation classes. Is there a way to check if at least > all function > names of the API are defined by the class and if their parameter lists > fit the API? A way > to test this would save me a lot of time..
To make it short: no, there is no reliable way to test this. To make it longer: yes, you can, with several kludges (and limitations), test this sort of thing. For example, start by running a dir() on the interface definition class, and for each name you get returned check whether it is a callable/function, then in case it is, have a look at the corresponding class claiming to implement the interface, check if the name exists, if it is a callable, and whether the method signature is appopriately similar. Most of the latter can be done using the introspection support present in Python, which is nicely wrapped up for you in a module and whose documentation you can find at: http://www.python.org/doc/2.4.2/lib/module-inspect.html Be aware that this does not check for methods which might be added at runtime to a class, that you might have to create more elaborate tests to check whether a class that might be callable has the correct method signature, and several other quirks (such as a function in the interface prototype taking five arguments, whereas in the class definition taking only a single catch-all argument). See how much of a can of worm this is? That's why you should rely on duck-typing: if it quacks like a duck and walks like a duck, chances are you really have a duck. And the only reliable way to test that is to let it run. --- Heiko. -- http://mail.python.org/mailman/listinfo/python-list
