view_tree.py

from pathlib import Path
from itertools import islice
import sys

# prefix components:
space =  '    '
branch = '│   '
# pointers:
tee =    '├── '
last =   '└── '


def tree(dir_path: Path, level: int=-1, limit_to_directories: bool=False,
         length_limit: int=1000):
    """Given a directory Path object print a visual tree structure"""
    dir_path = Path(dir_path) # accept string coerceable to Path
    files = 0
    directories = 0
    def inner(dir_path: Path, prefix: str='', level=-1):
        nonlocal files, directories
        if not level: 
            return # 0, stop iterating
        if limit_to_directories:
            contents = [d for d in dir_path.iterdir() if d.is_dir()]
        else: 
            contents = list(dir_path.iterdir())
        pointers = [tee] * (len(contents) - 1) + [last]
        for pointer, path in zip(pointers, contents):
            if path.is_dir():
                yield prefix + pointer + path.name
                directories += 1
                extension = branch if pointer == tee else space 
                yield from inner(path, prefix=prefix+extension, level=level-1)
            elif not limit_to_directories:
                yield prefix + pointer + path.name
                files += 1
    print(dir_path.name)
    iterator = inner(dir_path, level=level)
    for line in islice(iterator, length_limit):
        print(line)
    if next(iterator, None):
        print(f'... length_limit, {length_limit}, reached, counted:')
    print(f'\n{directories} directories' + (f', {files} files' if files else ''))

p = sys.argv[1] if len(sys.argv) > 1 else '.'
pp = sys.argv[2] if len(sys.argv) > 2 else ''
dir = Path(p)
for line in tree(dir, limit_to_directories=True):
    print(line)