Python - passing string and specific lists, combined into function

i want to pass string (dirPath + dirName[x]) to a function

i already tried 3 times to combining string and a specific list (only dirName[x])

it seems that python just rejecting it anyway even if i already convert it to another type.

is anyone know how i pass this string to Function?

layer = 0
dirName = []
#dummy value layer = 4,  dirName = [/a,/b,/c,/d], dirBruteForce(layer,vault)

def dirBruteForce(layer,dirPath):
if layer > 0 :
    #call again to make layered dir
    for x in range(len(dirName)):
        dirBruteForce(layer - 1, dirPath + dirName[x]) ##this line
#call end of the dir
elif layer is 0 :
    for x in range(len(dirName)):
        try:
            os.makedirs(dirPath)
            print(dirPath)
        except Exception as e:
            pass
###

try1:

dirBruteForce(layer - 1, dirPath + dirName[x])
TypeError: can only concatenate list (not "str") to list

try2:

list = [dirPath,str(dirName[x])]
dir = ''.join(list)
dirBruteForce(layer - 1, dir)

error2:

dir = ''.join(list)
TypeError: sequence item 0: expected str instance, list found

try3:

dir = ''.join([dirPath,dirName[x]])
dirBruteForce(layer - 1, dir)

error3:

dir = '-'.join([dirPath,dirName[x]])
TypeError: sequence item 0: expected str instance, list found

Copyright Notice：Content Author:「Ilyasofficial」，Reproduced under the CC 4.0 BY-SA copyright license with a link to the original source and this disclaimer.
Link to original article：https://stackoverflow.com/questions/46158628/python-passing-string-and-specific-lists-combined-into-function