Question

I have a module that imports a module, but in some cases the module being imported may not exist. After the module is imported there is a class inherits from a class the imported module. If I was to catch the ImportError exception in the case the module doesn’t exist, how can I stop Python from parsing the rest of the module? I’m open to other solutions if that’s not possible.

Here is a basic example (selfaware.py):

try:     from skynet import SkyNet except ImportError:     class SelfAwareSkyNet():         pass     exit_module_parsing_here()  class SelfAwareSkyNet(SkyNet):     pass 

The only ways I can think to do this is:

• Before importing the selfaware.py module, check if the skynet module is available, and simply pass or create a stub class. This will cause DRY if selfaware.py is imported multiple times.

• Within selfaware.py have the class defined withing the try block. e.g.:

  try:     from skynet import SkyNet     class SelfAwareSkyNet(SkyNet):         pass except ImportError:     class SelfAwareSkyNet():         pass 

Answer 1

You could use:

try:    from skynet import SkyNet    inherit_from = SkyNet except ImportError:    inherit_from = object  class SelfAwareSkyeNet(inherit_from):     pass 

This works only if the implementation do not differ.

Edit: New solution after comment.