Iterating through directories throws non-iterator error

Question

I tried exact code on this page to iterate through subdirectories. However, I am getting following error:

  File "dir_iterator.py", line 29, in <module>
    for x in it:
TypeError: iter() returned non-iterator of type 'iterdir'

Where is the problem and how can it be solved?

Note: I am using Python version 3.5.3 on Debian Stable Linux

Edit: As suggested by @DroidX86 in comments below, I am posting the code verbatim as copied from this link:

import os

class iterdir(object):
    def __init__(self, path, deep=False):
    self._root = path
    self._files = None
    self.deep = deep
    def __iter__(self):
    return self
    def next(self):
    if self._files:
        join = os.path.join
        d = self._files.pop()
        r = join(self._root, d)
        if self.deep and os.path.isdir(r):
        self._files += [join(d,n) for n in os.listdir(r)]
    elif self._files is None:
        self._files = os.listdir(self._root)
    if self._files:
        return self._files[-1]
    else:
        raise StopIteration


# sample:
#   a deep traversal of directories which starts with a vowel
#
it = iterdir('.')
for x in it:
    p = os.path.basename(x)
    it.deep = p[0].lower() in "aeiou"
    print x

Answer 1

The code is written for python2. For any reason, if you want it to run with python3, change def next: to def __next__: and print x to print(x). These two changes required to convert the python2 code in the link to python3.

import os


class iterdir(object):
    def __init__(self, path, deep=False):
        self._root = path
        self._files = None
        self.deep = deep

    def __iter__(self):
        return self

    def __next__(self):
        if self._files:
            join = os.path.join
            d = self._files.pop()
            r = join(self._root, d)
            if self.deep and os.path.isdir(r):
                self._files += [join(d, n) for n in os.listdir(r)]
        elif self._files is None:
            self._files = os.listdir(self._root)

        if self._files:
            return self._files[-1]
        else:
            raise StopIteration


# sample:
#   a deep traversal of directories which starts with a vowel
#
it = iterdir('.')
for x in it:
    p = os.path.basename(x)
    it.deep = p[0].lower() in "aeiou"
    print(x)