Iterate through folders, then subfolders and print filenames with path to text file

Question

I am trying to use python to create the files needed to run some other software in batch. For part of this I need to produce a text file that loads the needed data files int

Answer 1

Charles' answer is good, but can be improved upon to increase speed and efficiency. Each item produced by os.walk() (See docs) is a tuple of three items. Those items are:

1. The working directory
2. A list of strings naming any sub-directories present in the working directory
3. A list of files present in the working directory

Knowing this, much of Charles' code can be condensed with the modification of a forloop:

import os

def list_files(dir):
    r = []
    for root, dirs, files in os.walk(dir):
        for name in files:
            r.append(os.path.join(root, name))
    return r

Answer 2

Use os.walk(). The following will output a list of all files within the subdirectories of "dir". The results can be manipulated to suit you needs:

import os                                                                                                             
                                                                                                                      
def list_files(dir):                                                                                                  
    r = []                                                                                                            
    subdirs = [x[0] for x in os.walk(dir)]                                                                            
    for subdir in subdirs:                                                                                            
        files = os.walk(subdir).next()[2]                                                                             
        if (len(files) > 0):                                                                                          
            for file in files:                                                                                        
                r.append(os.path.join(subdir, file))                                                                         
    return r                                                                                                          

For python 3, change next() to __next__().