Python 3: Walk Directory, List Files

os.walk(dirPath)

visit dirPath and EVERY nested sub directory of dirPath.

For each dir visit, starting with dirPath, returns a generator (a list-like thing), where each element is a tuple of this format:

• currentDirPath → full path of current directory.
• dirNames → list of subdir names (not full path) that are immediate children.
• fileNames → list of file names (not full path) that are immediate children.

If the current dir doesn't have subdir or files, it'll be a empty list.

Note: os.walk is new in Python 3, but also available in python 2.7.x.

In older version of Python 2, you'll need to use os.path.walk. 〔see Python 2: Walk Directory, List Files〕

Here's a example of using os.walk to visit all files in a directory and all its subdirectories.

# traverse dir

import os

input_path = "/Users/xah/web/xahlee_info/python/"

for dir_path, subdir_list, file_list in os.walk(input_path):
    for fname in file_list:
        full_path = os.path.join(dir_path, fname)
        print(full_path)

# output sample:
# /Users/xah/web/xahlee_info/python/stateful_func.html
# /Users/xah/web/xahlee_info/python/function_def.html
# /Users/xah/web/xahlee_info/python/python3_traverse_dir.html
# more

Return Type of os.walk

the os.walk returns a generator object.

import os

print(os.walk("/home/"))
# <generator object walk at 0xb705561c>

print(type(os.walk("/home/")))
# <class 'generator'>

“generator” is like a list, but more efficient because it doesn't actually compute the result until needed. You can convert the result of generator into a list by calling list().

import os

print( list( os.walk("/home/") ) )
# [('/home/', [], [])]