How to do a recursive sub-folder search and return files in a list?

Solution 1:

You should be using the dirpath which you call root. The dirnames are supplied so you can prune it if there are folders that you don't wish os.walk to recurse into.

import os
result = [os.path.join(dp, f) for dp, dn, filenames in os.walk(PATH) for f in filenames if os.path.splitext(f)[1] == '.txt']

Edit:

After the latest downvote, it occurred to me that glob is a better tool for selecting by extension.

import os
from glob import glob
result = [y for x in os.walk(PATH) for y in glob(os.path.join(x[0], '*.txt'))]

Also a generator version

from itertools import chain
result = (chain.from_iterable(glob(os.path.join(x[0], '*.txt')) for x in os.walk('.')))

Edit2 for Python 3.4+

from pathlib import Path
result = list(Path(".").rglob("*.[tT][xX][tT]"))

Solution 2:

Changed in Python 3.5: Support for recursive globs using “**”.

glob.glob() got a new recursive parameter.

If you want to get every .txt file under my_path (recursively including subdirs):

import glob

files = glob.glob(my_path + '/**/*.txt', recursive=True)

# my_path/     the dir
# **/       every file and dir under my_path
# *.txt     every file that ends with '.txt'

If you need an iterator you can use iglob as an alternative:

for file in glob.iglob(my_path, recursive=True):
    # ...