Entry

Should __getattr__ increment the reference count before it returns the appropriate attribute, or not? writing a Python module in C

May 16th, 2000 07:17
unknown unknown, Gordon McMillan

It should incref the attribute and leave the owner alone.

Imagine a sequence like this:
 newref = a.b # here's your __getattr__
 a = None
Now a's refcount drops. If it drops to 0, it gets deallocated, which 
will decref b. Without an incref in __getattr__, the user would have 
an invalid reference.