On Tue, Jan 06, 2015 at 04:14:38AM +1100, Chris Angelico wrote:
On Tue, Jan 6, 2015 at 4:10 AM, Steven D'Aprano <steve@pearwood.info> wrote:
* If you want to apply globs to something other than file names, the right module to use would probably be globbing.generic (or possible fnmatch directly).
To clarify: Do you mean "something other than names of currently-existing files", or "something other than valid names for the local file system", or something else? For instance, suppose you write an unarchiver (in case we don't have enough of them already, of course), and you can "python unarchive.py archivename *.txt" to extract all files matching *.txt. The globbing would be done against some sort of internal index, but the names would have to be valid for the local file system, or you wouldn't be able to create them. Which module should you use?
fnmatch. I've had a look inside glob.py and it calls os.listdir directly, so you cannot use glob to match things other than actual existing files. (Well, I suppose you could if you monkey-patched the module, but lets not go there.) fnmatch, on the other hand, provides the right tool for matching names other than actual file names: fnmatch.filter(names, pattern). (Well, almost the right tool -- it has a few issues too.) To summarise: - the glob module returns only actual files in the file system; - the new globbing package will do the same, except it will use platform-specific wildcards where possible; - fnmatch continues as Python's generic "match globs against arbitrary strings" module (despite the name). -- Steven