os.walk and recursive deletion

[Martin Marcher]

Hello,

I'm playing around with os.walk and I made up del_tree(path) which I
think is correct (in terms of the algorithm, but not as python wants
it :)).

As soon as some directory is deleted the iterator of os.walk chokes.
OK that is somehow clear to me as it can't be valid anymore since it
can't go to the just deleted directory but it is in the iterator.

I generated the test data with (bash, don't know of other shell
expansion features)

# root="test"
# mkdir $root
# mkdir -p
# $root/{a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}/{a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}
# touch $root/{a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}/{0,1,2,3,4,5,6,7,8,9}
# touch $root/{a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}/{a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}/{0,1,2,3,4,5,6,7,8,9}

Here goes the script, as far as I tested it it runs fine in test mode.
Now that is just use the print statements like attached below. as soon
as os.rmdir and os.unlink are involved the iterator chokes. How do I
get around that, or what should I use to be able to recursively delete
everything under a certain subdir?

#--snip
import sys
import os
import unittest

def del_tree(path):
   walker = os.walk(path)
   for entry in walker:
      cwd = entry[0]
      subdirs = entry[1]
      files = entry[2]
      print "Checking directory: %s" %(cwd, )
      if files:
         for file in files:
            file = os.path.join(cwd, file)
            print "The file is now: %s" % (file, )
            #os.unlink(file)
         print "OK directory %s has no more files, checking for
subdirs..." % (cwd, )
      else:
         print "OK directory %s NEVER HAD FILES, checking for
subdirs..." % (cwd, )
      if not subdirs:
         print "We can delete: %s" % (cwd, )
         #os.rmdir(cwd)
      else:
         for subdir in subdirs:
            subdir = os.path.join(cwd, subdir)
            print "We need to recurse into: %s" % (subdir, )
            del_tree(subdir)
   #os.rmdir(path)
   print "Removing: %s" % (path, )
#--snap
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