Python recursive folder read

I have a C++/Obj-C background and I am just discovering Python (been writing it for about an hour).
I am writing a script to recursively read the contents of text files in a folder structure.

The problem I have is the code I have written will only work for one folder deep. I can see why in the code (see #hardcoded path), I just don’t know how I can move forward with Python since my experience with it is only brand new.

Python Code:

import os
import sys

rootdir = sys.argv[1]

for root, subFolders, files in os.walk(rootdir):

    for folder in subFolders:
        outfileName = rootdir + "https://stackoverflow.com/" + folder + "/py-outfile.txt" # hardcoded path
        folderOut = open( outfileName, 'w' )
        print "outfileName is " + outfileName

        for file in files:
            filePath = rootdir + "https://stackoverflow.com/" + file
            f = open( filePath, 'r' )
            toWrite = f.read()
            print "Writing '" + toWrite + "' to" + filePath
            folderOut.write( toWrite )
            f.close()

        folderOut.close()