Reading/Writing files

Ethan Furman ethan at stoneleaf.us
Fri Mar 25 08:39:45 EDT 2011


On 3/18/2011 6:25 PM, Dan Stromberg wrote:
>
> On Fri, Mar 18, 2011 at 4:00 PM, Ethan Furman <ethan at stoneleaf.us
> <mailto:ethan at stoneleaf.us>> wrote:
>
>     Dan Stromberg wrote:
>
>
>         Are you on windows?
>
>         You probably should use / as your directory separator in Python,
>         not \.  In Python, and most other programming languages, \
>         starts an escape sequence, so to introduce a literal \, you
>         either need to prefix your string with r (r"\foo\bar") or double
>         your backslashes ("\\foo\\bar").
>
>         / works fine on windows, and doesn't require escaping ("/foo/bar").
>
>
>     Depends on your definition of 'fine'.
>
>     --> from glob import glob
>     --> from pprint import pprint as pp
>     --> pp(glob('c:/temp/*.pdf'))
>     ['c:/temp\\choose_python.pdf',
>     'c:/temp\\COA.pdf',
>     'c:/temp\\job_setup.pdf']
>
>     Visually ugly, and a pain to compare files and paths.
>
>
> I argue that the first is quite a bit more readable than the second:
> 'c:/temp/choose_python.pdf'
>     os.path.join([ 'c:', 'temp', 'choose_python.pdf' ])

I agree with your argument, but think that
     r'c:\temp\choose_python.pdf'
is even more readable still.  (Also, it wasn't I that suggested using
os.path.join() on everything.)


> Also, heard of os.path.normpath?  You probably shouldn't compare
> pathnames without it.

Thanks -- I've heard of it (mostly in the context of resolving relative 
path names (.. and such)), never checked it out... I'll read up on it.

~Ethan~



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