Working with vector output of a function (python)

Question

I need to work with different folder paths so I wrote this function to create them. Unfortunately I am not able to call the result vector. It always gives me a "None". By uncommenting the "#" I can see that the function works perfectly fine. I guess my mistakes lies somewhere in the last two lines, but that is what I found searching for how to store the result of a function.

Any ideas what I am doing wrong? Is there anything special to consider when saving the output of a function that is supposed to return a vector with multiple strings?

I'm using Python IDLE version 2.6.5 if that helps...

Thank you in advance for your help!

>>> def path_generator(path1,path2,path3):
        #res = []
        for i in path1:
            first_string = i
            for j in path2:
                second_string = first_string+"\\"+j
                for k in path3:
                    end_string = second_string+"\\"+k
                    #res.append(end_string)
        #print res
        del i,j,k,first_string,second_string

>>> origin = ["C:\\one","C:\\two"]
>>> subfolders = ["subfolder1","subfolder2","subfolder3","subfolder4"]
>>> files = ["testfile1.txt","testfile2.txt","testfile3.txt","testfile4.txt"]

>>> result = path_generator(origin,subfolders,files)
>>> print result
None

Answer 1

in order for your function to return anything you need to tell it to, i am assuming you want to return the list res

so add the line return res to the bottom of your function