Prevent TextIOWrapper from closing on GC in a Py2/Py3 compatible way

Question

What I need to accomplish:

Given a binary file, decode it in a couple different ways providing a TextIOBase API. Ideally these subseque

Answer 1

EDIT:

I found a much better solution (comparatively), but I will leave this answer in the event it is useful for anyone to learn from. (It is a pretty easy way to show off gc.garbage)

Please do not actually use what follows.

OLD:

I found a potential solution, though it is horrible:

What we can do is set up a cyclic reference in the destructor, which will hold off the GC event. We can then look at the garbage of gc to find these unreferenceable objects, break the cycle, and drop that reference.

In [1]: import io

In [2]: class MyTextIOWrapper(io.TextIOWrapper):
   ...:     def __del__(self):
   ...:         if not hasattr(self, '_cycle'):
   ...:             print "holding off GC"
   ...:             self._cycle = self
   ...:         else:
   ...:             print "getting GCed!"
   ...:

In [3]: def mangle(x):
   ...:     MyTextIOWrapper(x)
   ...:     

In [4]: f = io.open('example', mode='rb')

In [5]: mangle(f)
holding off GC

In [6]: f.closed
Out[6]: False

In [7]: import gc

In [8]: gc.garbage
Out[8]: []

In [9]: gc.collect()
Out[9]: 34

In [10]: gc.garbage
Out[10]: [<_io.TextIOWrapper name='example' encoding='UTF-8'>]

In [11]: gc.garbage[0]._cycle=False

In [12]: del gc.garbage[0]
getting GCed!

In [13]: f.closed
Out[13]: True

Truthfully this is a pretty horrific workaround, but it could be transparent to the API I am delivering. Still I would prefer a way to override the __del__ of IOBase.