os.walk() ValueError: need more than 1 value to unpack

Question

Alright, I'm working with a Bioloid Premium humanoid robot, and Mac OS X will not recognize it. So I wrote a Python script to detect changes in my /dev/ folder because any connection on a Linux-based system is still given a reference via a file descriptor. My code should work, however, when assigning three variable to the values that are returned by os.walk(top), I get a ValueError. Anyone know how I can fix this? I've used this function in the past, and it hasn't given me any trouble. My script btw is very rough, I wrote it in about 5 minutes or so.

Code:

root_o, dir_o, files_o = os.walk(top)

and the error is as follows.

Traceback (most recent call last):
  File "detectdevs.py", line 15, in <module>
    findDevs()
  File "detectdevs.py", line 11, in findDevs
    root_o, dir_o, files_o = os.walk(top)
ValueError: need more than 1 value to unpack

I did search around stackoverflow, and none of the ValueError issues I saw reference the os.walk() function.

Answer 1

Try this

for root_o, dir_o, files_o in os.walk(top)
    print root_o, dir_o, files_o

os.walk is a generator and you need to iterate over it.

Answer 2

os.walk returns an iterator that yields three-tuples, not a three-tuple:

for root, dirs, files in os.walk(top):
    # do stuff with root, dirs, and files

 

    In [7]: os.walk('.')
    Out[7]: <generator object walk at 0x1707050>

    In [8]: next(os.walk('.'))
    Out[8]:
    ('.',
     ['.vim',
      '.git',
       ...],
     ['.inputrc',
      ...])