变量和模块的实例检查

Question

I have a list of strings, which all are modules that are imported (I parsed the __init__.py file earlier for some other validation). For example mods = ['mod_one', 'mod_two', 'mod_three'] . I now need to verify that all of these are an instance of a pre-defined superclass ( skeleton.py ) - like

for x in mods:
    if not isinstance(x.Operation,skeleton.OperationSkeleton): 
        print("error with: "+x)`

My problem is that x is in this case a string - obviously, but is the name of the imported module I want to check. The string doesn't have a Operation ..

And odd enough.. for testing purpose did I try to

print(isinstance(mod_one.Operation,skeleton.OperationSkeleton))

and it prints False . But in mod_one.py the OperationSkeleton is imported from skeleton and class Clustering(ClusteringSkeleton): is created.

Answer 1

If your modules are already imported, you can access them by their name in the sys.modules mapping :

import sys

for x in mods:
    mod = sys.modules[x]
    if not issubclass(mod.Operation, skeleton.OperationSkeleton): 

You need to use issubclass() here as Operation is not an instance.