How can I search sub-folders using glob.glob module?

In Python 3.5 and newer use the new recursive **/ functionality:

configfiles = glob.glob('C:/Users/sam/Desktop/file1/**/*.txt', recursive=True)

When recursive is set, ** followed by a path separator matches 0 or more subdirectories.

In earlier Python versions, glob.glob() cannot list files in subdirectories recursively.

In that case I'd use os.walk() combined with fnmatch.filter() instead:

import os
import fnmatch

path = 'C:/Users/sam/Desktop/file1'

configfiles = [os.path.join(dirpath, f)
    for dirpath, dirnames, files in os.walk(path)
    for f in fnmatch.filter(files, '*.txt')]

This'll walk your directories recursively and return all absolute pathnames to matching .txt files. In this specific case the fnmatch.filter() may be overkill, you could also use a .endswith() test:

import os

path = 'C:/Users/sam/Desktop/file1'

configfiles = [os.path.join(dirpath, f)
    for dirpath, dirnames, files in os.walk(path)
    for f in files if f.endswith('.txt')]

To find files in immediate subdirectories:

configfiles = glob.glob(r'C:\Users\sam\Desktop\*\*.txt')

For a recursive version that traverse all subdirectories, you could use ** and pass recursive=True since Python 3.5:

configfiles = glob.glob(r'C:\Users\sam\Desktop\**\*.txt', recursive=True)

Both function calls return lists. You could use glob.iglob() to return paths one by one. Or use pathlib:

from pathlib import Path

path = Path(r'C:\Users\sam\Desktop')
txt_files_only_subdirs = path.glob('*/*.txt')
txt_files_all_recursively = path.rglob('*.txt') # including the current dir

Both methods return iterators (you can get paths one by one).

The glob2 package supports wild cards and is reasonably fast

code = '''
import glob2
glob2.glob("files/*/**")
'''
timeit.timeit(code, number=1)

On my laptop it takes approximately 2 seconds to match >60,000 file paths.

You can use Formic with Python 2.6

import formic
fileset = formic.FileSet(include="**/*.txt", directory="C:/Users/sam/Desktop/")

Disclosure - I am the author of this package.