[Python-Dev] Possible py3k io wierdness (original) (raw)

Brian Quinlan brian at sweetapp.com
Sun Apr 12 12:49:37 CEST 2009

I've added a new proposed patch to: http://bugs.python.org/issue5700

The idea is:

only IOBase implements close() (though a subclass can override close without causing problems so long as it calls super().close() or calls .flush() and ._close() directly)
change IOBase.close to call .flush() and then ._close()
.flush() invokes super().flush() in every class except IOBase
._close() invokes super()._close() in every class except IOBase
FileIO is implemented in Python in _pyio.py so that it can have the same base class as the other Python-implemented files classes
tests verify that .flush() is not called after the file is closed
tests verify that ._close()/.flush() calls are propagated correctly

On nice side effect is that inheritance is a lot easier and MI works as expected i.e.

class DebugClass(IOBase): def flush(self): print() super().flush() def _close(self): print( super()._close()

class MyClass(FileIO, DebugClass): # whatever order makes sense ...

m = MyClass(...) m.close()

Will call:

Cheers, Brian