This is a common error when creating a zlib.DecompIO(f):

MemoryError: memory allocation failed, allocating 32768 bytes

Obviously the buffer is necessary (for any streams you don't control the creation of, almost always w/ wbits=15), but that's a third of available ram, and sometimes the GC doesn't purge the old one in time to create the new one, or because of fragmentation there's no contiguous space available.

Could we add a function to reset the internal state? IE decomp.reset(f) That way it could reuse the previous allocation, eliminating the risk of an OOM if resetting instead of creating anew.

Would you be willing to sponsor this work? Yes, if the concept is agreed to.