The rap against "while True:" loops

Luis Zarrabeitia kyrie at
Mon Oct 12 18:59:34 CEST 2009

On Monday 12 October 2009 09:47:23 am Xavier Ho wrote:
> On Mon, Oct 12, 2009 at 11:32 PM, Luis Zarrabeitia <kyrie at> wrote:
> > Actually, in python, this works even better:
> >
> > for lin in iter(file_object.readline, ""):
> >    ... do something with lin
> What about ....
> >>> with open(path_string) as f:
> >>>     for line in f:
> >>>         # do something


You are right, of course!

Even my for should've been:

for lin in file_object:

and nothing more.

I use that iter "trick" only when I don't want the buffering (like, when I'm 
reading from stdin in a squid authenticator helper).

I guess that the 'for line in f' is so... natural for me, that the only reason 
I could think for writing "while True" for a file iteration was when I needed 
to use readline explicitly.

But yes, "with"!

Luis Zarrabeitia (aka Kyrie)
Fac. de Matemática y Computación, UH.

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