os.walk() 递归获取 dir 下所有 file path

os.walk 递归地遍历每个文件夹，返回 generator

for i, (root, dirs, files) in enumerate(os.walk('example')):
    print i
    print 'root:', root
    print 'subdirs:', dirs
    print 'files:', files
    print

0
root: example
subdirs: ['labelTxt', 'images']
files: []

1
root: example/labelTxt
subdirs: []
files: ['P1234.txt', 'P1888.txt', 'P0706.txt', 'P0770.txt', 'P1088.txt', 'P2598.txt', 'P2709.txt']

2
root: example/images
subdirs: []
files: ['P1888.png', 'P0706.png', 'P0770.png', 'P1088.png', 'P2709.png', 'P2598.png', 'P1234.png']

example 路径：

example 
├── images
│   ├── P0706.png
│   ├── P0770.png
│   ├── P1088.png
│   ├── P1234.png
│   ├── P1888.png
│   ├── P2598.png
│   └── P2709.png
└── labelTxt
    ├── P0706.txt
    ├── P0770.txt
    ├── P1088.txt
    ├── P1234.txt
    ├── P1888.txt
    ├── P2598.txt
    └── P2709.txt

2 directories, 14 files

GetFileFromThisRootDir 获取 Root 下的所有 files path

def GetFileFromThisRootDir(dir, ext=None):
    allfiles = []
    needExtFilter = (ext != None)

    # os.walk() generate (root, dirs, files)
    # root: root dir (string)
    # dirs: root subdirs (list)
    # files: root files (list)
    for root, dirs, files in os.walk(dir):
        for filespath in files:
            filepath = os.path.join(root, filespath)  # root 已变成 files 的上一级目录了 
            extension = os.path.splitext(filepath)[1][1:]
            if needExtFilter and extension in ext:  # limit exts, such as [.png, .jpg]
                allfiles.append(filepath)
            elif not needExtFilter:
                allfiles.append(filepath)
    return allfiles

if __name__ == '__main__':
    for file_path in GetFileFromThisRootDir('example'):
        print file_path

example/labelTxt/P1234.txt
example/labelTxt/P1888.txt
example/labelTxt/P0706.txt
example/labelTxt/P0770.txt
example/labelTxt/P1088.txt
example/labelTxt/P2598.txt
example/labelTxt/P2709.txt
example/images/P1888.png
example/images/P0706.png
example/images/P0770.png
example/images/P1088.png
example/images/P2709.png
example/images/P2598.png
example/images/P1234.png