Cyclic references et C libraries
Martin v. Löwis
martin at v.loewis.de
Sun Aug 31 03:28:04 CEST 2003
Fabien SK <fabsk+news at free.fr> writes:
> One solution would be to wrap the parent objet in a new class
> (forwarding all the calls to the parent object). In the "__del__"
> method of this class, I would clean the list of children object, and
> then remove the reference on the parent objet so its "__del__" method
> will be called. Am I right ?
I would not wrap the parent object, but the file handle. So do
def __init__(self, *args):
self.h = lib_open(*args)
def read_section(self, *args):
return lib_read_section(self.h, *args)
def __init__(self, ...):
# self.handle = lib_open(...)
Then, the Handle class won't participate in a cycle, and it can safely
have an __del__.
> Last question: why does the python file objects not have a "__del__"
> method ? How the file can be closed when the last reference is remove
If a Python type is implemented in C, it does not need to have an
__del__. Instead, having a tp_del slot in its PyTypeObject C structure
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