How to avoid certain directories when using os.walk?

[Sean DiZazzo]

On Oct 29, 10:17 pm, Chris Rebert <c... at rebertia.com> wrote:
> On Thu, Oct 29, 2009 at 9:53 PM, Peng Yu <pengyu... at gmail.com> wrote:
> > I don't see a way to avoid walking over directories of certain names
> > with os.walk. For example, I don't want os.walk return files whose
> > path include '/backup/'. Is there a way to do so? Otherwise, maybe I
> > will have to make my own program. Thank you!
>
> Read the docs! (http://docs.python.org/library/os.html#os.walk):
>
> """
> os.walk(top[, topdown=True[, onerror=None[, followlinks=False]]])
>
>     Generate the file names in a directory tree by walking the tree
> either top-down or bottom-up. For each directory in the tree rooted at
> directory top (including top itself), it yields a 3-tuple (dirpath,
> dirnames, filenames).
> [...]
>     When topdown is True, the caller can modify the dirnames list
> in-place (perhaps using del or slice assignment), and walk() will only
> recurse into the subdirectories whose names remain in dirnames; this
> can be used to prune the search, impose a specific order of visiting,
> or even to inform walk() about directories the caller creates or
> renames before it resumes walk() again.
> """
>
> They even include a specific code example of how to skip unwanted
> subdirectories.
>
> Cheers,
> Chris
> --http://blog.rebertia.com

You will run into problems however if you want to delete from a tree
while ignoring certain named directories.  Directories must be empty
before they can be deleted, so you must use "topdown=False", but to
prune a search you must use "topdown=True".  At least I think that was
the problem I had with my deletion script a while back.

~Sean