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Groups > comp.lang.python > #103042
| From | Chris Angelico <rosuav@gmail.com> |
|---|---|
| Newsgroups | comp.lang.python |
| Subject | Re: Will file be closed automatically in a "for ... in open..." statement? |
| Date | 2016-02-17 15:36 +1100 |
| Message-ID | <mailman.196.1455683816.22075.python-list@python.org> (permalink) |
| References | <acc702dc-dccd-49ca-857f-b256ad619123@googlegroups.com> <230cfde5-e6f2-45fe-9739-e56c5c7739ab@googlegroups.com> |
On Wed, Feb 17, 2016 at 3:04 PM, <jfong@ms4.hinet.net> wrote:
> Thanks for these detailed explanation. Both statements will close file automatically sooner or later and, when considering the exceptions, "with" is better. Hope my understanding is right.
>
> But, just curious, how do you know the "for" will do it? I can't find any document about it from every sources I know. Very depressed:-(
>
It's not the 'for' loop that does it. The for loop is kinda like this:
_temp = open("foo.txt")
_temp.read() # do stuff, do stuff
_temp = None
When you stop holding onto an object, Python can get rid of it. When
that happens is not promised, though - and if you have a reference
loop, it might hang around for a long time. But when a file object is
disposed of, the underlying file will get closed.
ChrisA
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Will file be closed automatically in a "for ... in open..." statement? jfong@ms4.hinet.net - 2016-02-16 00:39 -0800
Re: Will file be closed automatically in a "for ... in open..." statement? Chris Angelico <rosuav@gmail.com> - 2016-02-16 20:16 +1100
Re: Will file be closed automatically in a "for ... in open..." statement? Cameron Simpson <cs@zip.com.au> - 2016-02-16 20:24 +1100
Re: Will file be closed automatically in a "for ... in open..." statement? Terry Reedy <tjreedy@udel.edu> - 2016-02-16 04:41 -0500
Re: Will file be closed automatically in a "for ... in open..." statement? jfong@ms4.hinet.net - 2016-02-16 20:04 -0800
Re: Will file be closed automatically in a "for ... in open..." statement? Chris Angelico <rosuav@gmail.com> - 2016-02-17 15:36 +1100
Re: Will file be closed automatically in a "for ... in open..." statement? Raspberry Aether <raspberryaether@e-s.invalid> - 2016-02-16 23:42 -0500
Re: Will file be closed automatically in a "for ... in open..." statement? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2016-02-17 16:51 +1100
Re: Will file be closed automatically in a "for ... in open..." statement? Tim Chase <python.list@tim.thechases.com> - 2016-02-17 20:32 -0600
Re: Will file be closed automatically in a "for ... in open..." statement? jfong@ms4.hinet.net - 2016-02-17 17:29 -0800
Re: Will file be closed automatically in a "for ... in open..." statement? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-02-18 02:05 +0000
Re: Will file be closed automatically in a "for ... in open..." statement? Jeremy Leonard <jrmy.lnrd@gmail.com> - 2016-02-18 10:02 -0800
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