[Python-Dev] os.path.walk() lacks 'depth first' option

[Guido van Rossum]

How about this patch?

Index: os.py
===================================================================
RCS file: /cvsroot/python/python/dist/src/Lib/os.py,v
retrieving revision 1.70
diff -c -c -r1.70 os.py
*** os.py	25 Apr 2003 07:11:48 -0000	1.70
--- os.py	13 May 2003 15:40:21 -0000
***************
*** 203,209 ****
  
  __all__.extend(["makedirs", "removedirs", "renames"])
  
! def walk(top, topdown=True):
      """Directory tree generator.
  
      For each directory in the directory tree rooted at top (including top
--- 203,209 ----
  
  __all__.extend(["makedirs", "removedirs", "renames"])
  
! def walk(top, topdown=True, onerror=None):
      """Directory tree generator.
  
      For each directory in the directory tree rooted at top (including top
***************
*** 232,237 ****
--- 232,243 ----
      dirnames have already been generated by the time dirnames itself is
      generated.
  
+     By default errors from the os.listdir() call are ignored.  If
+     optional arg 'onerror' is specified, it should be a function;
+     it will be called with one argument, an exception instance.  It
+     can report the error to continue with the walk, or raise the
+     exception to abort the walk.
+ 
      Caution:  if you pass a relative pathname for top, don't change the
      current working directory between resumptions of walk.  walk never
      changes the current directory, and assumes that the client doesn't
***************
*** 259,265 ****
          # Note that listdir and error are globals in this module due
          # to earlier import-*.
          names = listdir(top)
!     except error:
          return
  
      dirs, nondirs = [], []
--- 265,273 ----
          # Note that listdir and error are globals in this module due
          # to earlier import-*.
          names = listdir(top)
!     except error, err:
!         if onerror is not None:
!             onerror(err)
          return
  
      dirs, nondirs = [], []
***************
*** 274,280 ****
      for name in dirs:
          path = join(top, name)
          if not islink(path):
!             for x in walk(path, topdown):
                  yield x
      if not topdown:
          yield top, dirs, nondirs
--- 282,288 ----
      for name in dirs:
          path = join(top, name)
          if not islink(path):
!             for x in walk(path, topdown, onerror):
                  yield x
      if not topdown:
          yield top, dirs, nondirs

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