Generic and pythonic implementation of the Depth First Search traversal algorithm

dfs.py

"""Generic and pythonic implementation of the Depth First Search traversal algorithm"""
from typing import Callable, List, Iterable,TypeVar,Hashable, MutableSequence
from pathlib import Path
from collections import deque

T = TypeVar('T', bound=Hashable)
S = TypeVar('S')

def iter_top(stack: MutableSequence[S]) -> Iterator[S]:
    """Iterate a stack as long as it is full, yielding the top every time"""
    while stack:
        yield stack.pop()


def dfs(root: T, neighbors_func: Callable[[T], Iterable[T]) -> Iterator[T]:
    """Iterate starting from root, going depth first
    `neighbors_func`: a function that returns an iterable of the nodes neighbors
        """
    stack = deque([root])
    visited_nodes = set()
    for item in (item for item in iter_top(stack)
                 if item not in visited_nodes):
        visited_nodes.add(item)
        stack.extend(neighbors_func(item))
        yield item

# Example usage:

def safe_iterdir(path: Path):
    return path.iterdir() if path.is_dir() else tuple()


def main():
    root = Path(Path.home()/'Desktop')
    path: Path
    print('\n'.join(str(path.resolve()) for path in dfs(root, safe_iterdir) if path.is_dir()))


if __name__ == '__main__':
    main()

The typing isn't completely correct, if someone here has more mypy experience than me feel free to comment!