\end{funcdesc}
\begin{funcdesc}{walk}{top\optional{, topdown\code{=True}
- \optional{, onerror\code{=None}\optional{,
- followlinks\code{=False}}}}}
+ \optional{, onerror\code{=None}}}}
\index{directory!walking}
\index{directory!traversal}
\function{walk()} generates the file names in a directory tree, by
to abort the walk. Note that the filename is available as the
\code{filename} attribute of the exception object.
-By default, \function{walk()} will not walk down into symbolic links that
-resolve to directories. Set \var{followlinks} to True to visit directories
-pointed to by symlinks, on systems that support them.
-
\versionadded[The \var{followlinks} parameter]{2.6}
-\begin{notice}
-Be aware that setting \var{followlinks} to true can lead to infinite recursion
-if a link points to a parent directory of itself. \function{walk()} does not
-keep track of the directories it visited already.
-\end{notice}
-
\begin{notice}
If you pass a relative pathname, don't change the current working
directory between resumptions of \function{walk()}. \function{walk()}
doesn't either.
\end{notice}
+\begin{notice}
+On systems that support symbolic links, links to subdirectories appear
+in \var{dirnames} lists, but \function{walk()} will not visit them
+(infinite loops are hard to avoid when following symbolic links).
+To visit linked directories, you can identify them with
+\code{os.path.islink(\var{path})}, and invoke \code{walk(\var{path})}
+on each directly.
+\end{notice}
+
This example displays the number of bytes taken by non-directory files
in each directory under the starting directory, except that it doesn't
look under any CVS subdirectory:
__all__.extend(["makedirs", "removedirs", "renames"])
-def walk(top, topdown=True, onerror=None, followlinks=False):
+def walk(top, topdown=True, onerror=None):
"""Directory tree generator.
For each directory in the directory tree rooted at top (including top
to abort the walk. Note that the filename is available as the
filename attribute of the exception object.
- By default, os.walk does not follow symbolic links to subdirectories on
- systems that support them. In order to get this functionality, set the
- optional argument 'followlinks' to true.
-
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
yield top, dirs, nondirs
for name in dirs:
path = join(top, name)
- if followlinks or not islink(path):
- for x in walk(path, topdown, onerror, followlinks):
+ if not islink(path):
+ for x in walk(path, topdown, onerror):
yield x
if not topdown:
yield top, dirs, nondirs
# SUB1/ a file kid and a directory kid
# tmp2
# SUB11/ no kids
- # SUB2/ a file kid and a dirsymlink kid
+ # SUB2/ just a file kid
# tmp3
- # link/ a symlink to TESTFN.2
- # TESTFN.2/
- # tmp4 a lone file
sub1_path = join(test_support.TESTFN, "SUB1")
sub11_path = join(sub1_path, "SUB11")
sub2_path = join(test_support.TESTFN, "SUB2")
tmp1_path = join(test_support.TESTFN, "tmp1")
tmp2_path = join(sub1_path, "tmp2")
tmp3_path = join(sub2_path, "tmp3")
- link_path = join(sub2_path, "link")
- t2_path = join(test_support.TESTFN + ".2")
- tmp4_path = join(test_support.TESTFN + ".2", "tmp4")
# Create stuff.
os.makedirs(sub11_path)
os.makedirs(sub2_path)
- os.makedirs(t2_path)
- for path in tmp1_path, tmp2_path, tmp3_path, tmp4_path:
+ for path in tmp1_path, tmp2_path, tmp3_path:
f = file(path, "w")
f.write("I'm " + path + " and proud of it. Blame test_os.\n")
f.close()
- if hasattr(os, "symlink"):
- os.symlink(os.path.join("..", "..", t2_path), link_path)
- else:
- # it must be a directory because the test expects that
- os.mkdir(link_path)
# Walk top-down.
all = list(os.walk(test_support.TESTFN))
self.assertEqual(all[0], (test_support.TESTFN, ["SUB1", "SUB2"], ["tmp1"]))
self.assertEqual(all[1 + flipped], (sub1_path, ["SUB11"], ["tmp2"]))
self.assertEqual(all[2 + flipped], (sub11_path, [], []))
- self.assertEqual(all[3 - 2 * flipped], (sub2_path, ["link"], ["tmp3"]))
+ self.assertEqual(all[3 - 2 * flipped], (sub2_path, [], ["tmp3"]))
# Prune the search.
all = []
dirs.remove('SUB1')
self.assertEqual(len(all), 2)
self.assertEqual(all[0], (test_support.TESTFN, ["SUB2"], ["tmp1"]))
- self.assertEqual(all[1], (sub2_path, ["link"], ["tmp3"]))
+ self.assertEqual(all[1], (sub2_path, [], ["tmp3"]))
# Walk bottom-up.
all = list(os.walk(test_support.TESTFN, topdown=False))
self.assertEqual(all[3], (test_support.TESTFN, ["SUB1", "SUB2"], ["tmp1"]))
self.assertEqual(all[flipped], (sub11_path, [], []))
self.assertEqual(all[flipped + 1], (sub1_path, ["SUB11"], ["tmp2"]))
- self.assertEqual(all[2 - 2 * flipped], (sub2_path, ["link"], ["tmp3"]))
-
- # Walk, following symlinks.
- for root, dirs, files in os.walk(test_support.TESTFN, followlinks=True):
- if root == link_path:
- self.assertEqual(dirs, [])
- self.assertEqual(files, ["tmp4"])
- break
- else:
- self.fail("Didn't follow symlink with followlinks=True")
-
+ self.assertEqual(all[2 - 2 * flipped], (sub2_path, [], ["tmp3"]))
# Tear everything down. This is a decent use for bottom-up on
# Windows, which doesn't have a recursive delete command. The
for name in files:
os.remove(join(root, name))
for name in dirs:
- dirname = join(root, name)
- if not os.path.islink(dirname):
- os.rmdir(dirname)
- else:
- os.remove(dirname)
+ os.rmdir(join(root, name))
os.rmdir(test_support.TESTFN)
- os.unlink(tmp4_path)
- os.rmdir(t2_path)
class MakedirTests (unittest.TestCase):
def setUp(self):
projects / python / commitdiff