[Python-Dev] del and tp_dealloc in the IO lib (original) (raw)

rdmurray at bitdance.com rdmurray at bitdance.com
Fri Jan 23 15:57:02 CET 2009

On Fri, 23 Jan 2009 at 11:57, Giovanni Bajo wrote:

The fact that file objects are collected and closed immediately in all reasonable use cases (and even in case of exceptions, that you mention, things get even better with the new semantic of the except clause) is a good property of Python. I regularly see people happy about it.

I have never assumed that python closed my files before the end of the program unless I told it to do so, and have always coded accordingly. To do otherwise strikes me as bad coding. I don't believe I ever considered that such an assumption was even thinkable: closing open files when I'm done with them is part of my set of "good programming" habits developed over years of coding, habits that I apply in any language in which I write code. (In fact, it took me a while before I was willing to let python take care of closing the files at program end...and even now I sometimes close files explicitly even in short programs.)

Closing file objects is a specific instance of a more general programming rule that goes something like "clean up when you are done". I do in general trust python to clean up python data structures because it knows better than I do when "done" arrives; but when I know when "done" is, I do the cleanup. I love the 'with' statement :)

--RDM

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