文件目录遍历

from nt import *
def walk(top, topdown=True, onerror=None):
     
    from os.path import join, isdir, islink

    # We may not have read permission for top, in which case we can't
    # get a list of the files the directory contains.  os.path.walk
    # always suppressed the exception then, rather than blow up for a
    # minor reason when (say) a thousand readable directories are still
    # left to visit.  That logic is copied here.
    try:
        # 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 = [], []
    for name in names:
        if isdir(join(top, name)):
            dirs.append(name)
        else:
            nondirs.append(name)

    if topdown:
        yield top, dirs, nondirs
    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

 

******************************************

#以下为测试代码

s=walk('D:/liyuan1',False)
for n in s:
    print n

 

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

topdown=True运行结果

('D:/liyuan1', ['liyuan2'], ['liyuan1_aa1.txt', 'liyuan1_aa2.txt'])
('D:/liyuan1\\liyuan2', ['liyuan3'], ['liyuan2_aa1.txt', 'liyuan2_aa2.txt'])
('D:/liyuan1\\liyuan2\\liyuan3', ['liyuan4'], ['liyuan3_aa1.txt', 'liyuan3_aa2.txt'])
('D:/liyuan1\\liyuan2\\liyuan3\\liyuan4', [], ['liyuan4_aa1.txt', 'liyuan4_aa2.txt'])

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

topdown=False运行结果

('D:/liyuan1\\liyuan2\\liyuan3\\liyuan4', [], ['liyuan4_aa1.txt', 'liyuan4_aa2.txt'])
('D:/liyuan1\\liyuan2\\liyuan3', ['liyuan4'], ['liyuan3_aa1.txt', 'liyuan3_aa2.txt'])
('D:/liyuan1\\liyuan2', ['liyuan3'], ['liyuan2_aa1.txt', 'liyuan2_aa2.txt'])
('D:/liyuan1', ['liyuan2'], ['liyuan1_aa1.txt', 'liyuan1_aa2.txt'])