Generate the file names in a directory tree by walking the tree either top-down or bottom-up.
For each directory in the directory tree rooted at
self
(including
self
but excluding ‘.’ and ‘..’), the method yields a 3-tuple of
(dirpath, dirnames, filenames)
.
dirpath
是
Path
to the directory currently being walked,
dirnames
is a list of strings for the names of subdirectories in
dirpath
(excluding
'.'
and
'..'
)，和
filenames
is a list of strings for the names of the non-directory files in
dirpath
. To get a full path (which begins with
self
) to a file or directory in
dirpath
, do
dirpath / name
. Whether or not the lists are sorted is file system-dependent.
If the optional argument
top_down
is true (which is the default), the triple for a directory is generated before the triples for any of its subdirectories (directories are walked top-down). If
top_down
is false, the triple for a directory is generated after the triples for all of its subdirectories (directories are walked bottom-up). No matter the value of
top_down
, the list of subdirectories is retrieved before the triples for the directory and its subdirectories are walked.
当
top_down
is true, the caller can modify the
dirnames
list in-place (for example, using
del
or slice assignment), and
Path.walk()
will only recurse into the subdirectories whose names remain in
dirnames
. This can be used to prune the search, or to impose a specific order of visiting, or even to inform
Path.walk()
about directories the caller creates or renames before it resumes
Path.walk()
again. Modifying
dirnames
当
top_down
is false has no effect on the behavior of
Path.walk()
since the directories in
dirnames
have already been generated by the time
dirnames
is yielded to the caller.
By default, errors from
os.scandir()
are ignored. If the optional argument
on_error
is specified, it should be a callable; it will be called with one argument, an
OSError
instance. The callable can handle the error to continue the walk or re-raise it to stop the walk. Note that the filename is available as the
filename
attribute of the exception object.
默认情况下，
Path.walk()
does not follow symbolic links, and instead adds them to the
filenames
list. Set
follow_symlinks
to true to resolve symlinks and place them in
dirnames
and
filenames
as appropriate for their targets, and consequently visit directories pointed to by symlinks (where supported).
注意
Be aware that setting
follow_symlinks
to true can lead to infinite recursion if a link points to a parent directory of itself.
Path.walk()
does not keep track of the directories it has already visited.
注意
Path.walk()
assumes the directories it walks are not modified during execution. For example, if a directory from
dirnames
has been replaced with a symlink and
follow_symlinks
为 False，
Path.walk()
will still try to descend into it. To prevent such behavior, remove directories from
dirnames
酌情。
注意
不像
os.walk()
,
Path.walk()
lists symlinks to directories in
filenames
if
follow_symlinks
为 False。
This example displays the number of bytes used by all files in each directory, while ignoring
__pycache__
directories:
from pathlib import Path
for root, dirs, files in Path("cpython/Lib/concurrent").walk(on_error=print):
print(
root,
"consumes",
sum((root / file).stat().st_size for file in files),
"bytes in",
len(files),
"non-directory files"
)
if '__pycache__' in dirs:
dirs.remove('__pycache__')
This next example is a simple implementation of
shutil.rmtree()
. Walking the tree bottom-up is essential as
rmdir()
doesn’t allow deleting a directory before it is empty:
# Delete everything reachable from the directory "top".
# CAUTION: This is dangerous! For example, if top == Path('/'),
# it could delete all of your files.
for root, dirs, files in top.walk(top_down=False):
for name in files:
(root / name).unlink()
for name in dirs:
(root / name).rmdir()
3.12 版添加。
