On Wed, Oct 13, 2010 at 12:12 PM, Seebs <usenet-nos...@seebs.net> wrote:
> On 2010-10-13, Jonas H. <jo...@lophus.org> wrote:
> > Not really. Files will be closed when the garbage collector collects the
> > file object, but you can't be sure the GC will run within the next N
> > seconds/instructions or something like that. So you should *always* make
> > sure to close files after using them. That's what context managers were
> > introduced for.
>
> > with open('foobar') as fileobject:
> > do_something_with(fileobject)
>
> That makes sense. I don't think it'd quite work in this case, because I
> want to open several files all at once, do a ton of work that populates
> them with files, and then close them all.
>
> This is a nice idiom, though. In C, I've been sort of missing that idiom,
> which I first encountered in Ruby. (I mean, spelled differently, but the
> same basic thing.)
>
For opening multiple files, you can either nest the with statements:
with open('foobar1') as foobar1:
dosomethingwithfoobar1()
with open('foobar2') as foobar2:
dosomethingwithfoobar2()
dosomethingelsewithfoobar1()
or you can use the contextlib module to nest them in one line:
import contextlib
with contextlib.nested(open('foobar1'), open('foobar2')) as (foobar1,
foobar2):
dosomethingwithfoobar1and2()
> -s
> --
> Copyright 2010, all wrongs reversed. Peter Seebach /
> usenet-nos...@seebs.net
> http://www.seebs.net/log/ <-- lawsuits, religion, and funny pictures
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> opinions.
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