traverseda
/
cpython
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Patch #1273829: os.walk() now has a "followlinks" parameter. If set to 

True (which is not the default), it visits symlinks pointing to
directories.
This commit is contained in:
Georg Brandl 2007-03-16 08:22:40 +00:00
parent 8f06d02935
commit 8844e438b1
4 changed files with 57 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
Doc/lib/libos.tex
View File

@ -1233,7 +1233,8 @@ Availability: Macintosh, \UNIX, Windows.
\end{funcdesc}
\begin{funcdesc}{walk}{top\optional{, topdown\code{=True}
\optional{, onerror\code{=None}}}}
\optional{, onerror\code{=None}\optional{,
followlinks\code{=False}}}}}
\index{directory!walking}
\index{directory!traversal}
\function{walk()} generates the file names in a directory tree, by
@ -1273,6 +1274,16 @@ report the error to continue with the walk, or raise the exception
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.
\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()}
@ -1280,15 +1291,6 @@ never changes the current directory, and assumes that its caller
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:

10
Lib/os.py
View File

@ -221,7 +221,7 @@ def renames(old, new):
__all__.extend(["makedirs", "removedirs", "renames"])
def walk(top, topdown=True, onerror=None):
def walk(top, topdown=True, onerror=None, followlinks=False):
"""Directory tree generator.
For each directory in the directory tree rooted at top (including top
@ -257,6 +257,10 @@ def walk(top, topdown=True, onerror=None):
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
@ -300,8 +304,8 @@ def walk(top, topdown=True, onerror=None):
yield top, dirs, nondirs
for name in dirs:
path = join(top, name)
if not islink(path):
for x in walk(path, topdown, onerror):
if followlinks or not islink(path):
for x in walk(path, topdown, onerror, followlinks):
yield x
if not topdown:
yield top, dirs, nondirs

40
Lib/test/test_os.py
View File

@ -277,22 +277,34 @@ class WalkTests(unittest.TestCase):
# SUB1/ a file kid and a directory kid
# tmp2
# SUB11/ no kids
# SUB2/ just a file kid
# SUB2/ a file kid and a dirsymlink 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)
for path in tmp1_path, tmp2_path, tmp3_path:
os.makedirs(t2_path)
for path in tmp1_path, tmp2_path, tmp3_path, tmp4_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))
@ -305,7 +317,7 @@ class WalkTests(unittest.TestCase):
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, [], ["tmp3"]))
self.assertEqual(all[3 - 2 * flipped], (sub2_path, ["link"], ["tmp3"]))
# Prune the search.
all = []
@ -317,7 +329,7 @@ class WalkTests(unittest.TestCase):
dirs.remove('SUB1')
self.assertEqual(len(all), 2)
self.assertEqual(all[0], (test_support.TESTFN, ["SUB2"], ["tmp1"]))
self.assertEqual(all[1], (sub2_path, [], ["tmp3"]))
self.assertEqual(all[1], (sub2_path, ["link"], ["tmp3"]))
# Walk bottom-up.
all = list(os.walk(test_support.TESTFN, topdown=False))
@ -330,7 +342,17 @@ class WalkTests(unittest.TestCase):
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, [], ["tmp3"]))
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")
# Tear everything down. This is a decent use for bottom-up on
# Windows, which doesn't have a recursive delete command. The
@ -340,8 +362,14 @@ class WalkTests(unittest.TestCase):
for name in files:
os.remove(join(root, name))
for name in dirs:
os.rmdir(join(root, name))
dirname = join(root, name)
if not os.path.islink(dirname):
os.rmdir(dirname)
else:
os.remove(dirname)
os.rmdir(test_support.TESTFN)
os.unlink(tmp4_path)
os.rmdir(t2_path)
class MakedirTests (unittest.TestCase):
def setUp(self):

4
Misc/NEWS
View File

@ -179,6 +179,10 @@ Core and builtins
Library
-------
- Patch #1273829: os.walk() now has a "followlinks" parameter. If set to
True (which is not the default), it visits symlinks pointing to
directories.
- Bug #1681228: the webbrowser module now correctly uses the default
GNOME or KDE browser, depending on whether there is a session of one
of those present. Also, it tries the Windows default browser before