Will a Python generator be garbage collected if it will not be used any more but hasn't reached StopIteration yet?

Question

When a generator is not used any more, it should be garbage collected, right? I tried the following code but I am not sure which part I was wrong.

import wea         


        

Answer 1

The other answers have explained that gc.collect() won't garbage collect anything that still has references to it. There is still a live reference cd to the generator, so it will not be gc'ed until cd is deleted.

However in addition, the OP is creating a SECOND strong reference to the object using this line, which calls the weak reference object:

cdw = weakref.ref(cd)()

So if one were to do del cd and call gc.collect(), the generator would still not be gc'ed because cdw is also a reference.

To obtain an actual weak reference, do not call the weakref.ref object. Simply do this:

cdw = weakref.ref(cd)

Now when cd is deleted and garbage collected, the reference count will be zero and calling the weak reference will result in None, as expected.