[Tutor] try and file existence

[Cameron Simpson]

On 15Aug2015 15:20, Clayton Kirkwood <crk at godblessthe.us> wrote:
>> Behalf Of Laura Creighton
[..]
>> To: boB Stepp <robertvstepp at gmail.com>
>> In a message of Sat, 15 Aug 2015 14:24:21 -0500, boB Stepp writes:
>> >I understand your points, but wonder then what is the intended use for
>> >os.path.exists()?  That is, in what types of circumstances would it be
>> >both appropriate and safe to use?
>>
>> If you want to locate dangling symlinks,  os.path.exists will return False, so
>> the symlink is there, but the file it pointed to is long gone.
>
>Can't you do that with os.path.open() and get a value in os.path.status? (I
>think that is the thing to call)

Open does more that os.stat (which is what os.path.exists uses underneath).

There are plenty of times you will want to know a file exists but not have 
permission to open it. Also, open can have side effects if the target file is a 
device or a socket/pipe.

Always use the smallest thing you can to achieve an effect: stat is smaller 
than open.

Cheers,
Cameron Simpson <cs at zip.com.au>

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