[Python-Dev] urllib.urlretrieve() and handling 550 errors when reading from FTP

[Guido van Rossum]

> Bug #635453 reports that when you use urllib.urlretrieve() to read from 
> an FTP server and the file you are trying to get does not have the 
> proper permissions for you, you are given a listing of the directory 
> instead of an exception (this is all done by Lib/urllib.py:752).
> 
> Now this doesn't make sense to me and I suspect most people would agree. 
>   But having that explicit line there on top of it having been in the 
> file since it was renamed from urlopen way backin 1994 makes me hesitate 
> before I delete the line.
> 
> Anyone have issues if I ditch the line so an exception is raised instead 
> of getting a directory listing instead?

If you remove this, you won't be able to get a directory listing of
directories.  I tried this with and without the line; with that line
in, it gives a directlry listing, without it gives an IOError (Not a
regular file):

>>> urllib.urlretrieve("ftp://ftp.python.org/pub", "xyzzy")

So I'd be against deleting this, unless there's a different way to get
directory listings.

--Guido van Rossum (home page: http://www.python.org/~guido/)