You can’t directly add the method to the original type. However, you can subclass the type then substitute it in the built-in/global namespace, which achieves most of the effect desired. Unfortunately, objects created by literal syntax will continue to be of the vanilla type and won’t have your new methods/attributes. Here’s what it looks like … Read more
It should be noted that several of the answers here will patch the decorator for the entire test session rather than a single test instance; which may be undesirable. Here’s how to patch a decorator that only persists through a single test. Our unit to be tested with the undesired decorator: # app/uut.py from app.decorators … Read more
I suppose I should expand this answer, now that I’m older and wiser and know what’s going on. Better late than never. You can add a property to a class dynamically. But that’s the catch: you have to add it to the class. >>> class Foo(object): … pass … >>> foo = Foo() >>> foo.a … Read more
EDIT: It has been 9 years since I originally wrote this answer, and it deserves some cosmetic surgery to keep it current. You can see the last version before the edit here. You can’t call the overwritten method by name or keyword. That’s one of the many reasons why monkey patching should be avoided and … Read more
No, it’s not like any of those things. It’s simply the dynamic replacement of attributes at runtime. For instance, consider a class that has a method get_data. This method does an external lookup (on a database or web API, for example), and various other methods in the class call it. However, in a unit test, … Read more
In Python, there is a difference between functions and bound methods. >>> def foo(): … print “foo” … >>> class A: … def bar( self ): … print “bar” … >>> a = A() >>> foo <function foo at 0x00A98D70> >>> a.bar <bound method A.bar of <__main__.A instance at 0x00A9BC88>> >>> Bound methods have been … Read more