os.walk help

[hokiegal99]

Joe Francia wrote:
> Your code is trying to recurse into the list of directories in 'dirs', 
> but you are renaming these directories before it can get to them.  For 
> example, if dirs = ['baddir?*', 'gooddir', 'okdir'], you rename 
> 'baddir?*' to 'baddir--' and then os.walk tries to enter 'baddir?*' and 
> cannot find it.  You're better off building a list of paths to rename, 
> and then renaming them outside of the os.walk scope, or doing something 
> like...
> 
> dirs.remove(dname)
> dirs.append(newdname)
> 
> ...in your 'if' block.
> 
> Peace,
> Joe

So, which is better... rename in the os.walk scope or not? The below 
code works sometimes at others it produces this error:

ValueError: list.remove(x): x is not in list

setpath = raw_input("Path to the Directory: ")
def clean_names(setpath):
    bad = re.compile(r'%2f|%25|%20|[*?<>/\|\\]')
    for root, dirs, files in os.walk(setpath):
       for dname in dirs:
          badchars = bad.findall(dname)
          for badchar in badchars:
             newdname = dname.replace(badchar,'-')
             if newdname != dname:
                dirs.remove(dname)
                dirs.append(newdname)
                newpath = os.path.join(root, newdname)
                oldpath = os.path.join(root, dname)
                os.renames(oldpath, newpath)