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

def stringpath(path):
    # just a helper to get string of PosixPath
    return str(path)

from pathlib import Path
from stat import S_ISDIR
def tree_sftp(sftp, path='.', parent='/', prefix=''):
    """
    Loop through files to print it out
    for file in tree_sftp(sftp):
        print(file)
    """
    fullpath = Path(parent, path)
    strpath = stringpath(fullpath)

    dirs = sftp.listdir_attr(strpath)
    pointers = [tee] * (len(dirs) - 1) + [last]
    pdirs = [Path(fullpath, d.filename) for d in dirs]
    sdirs = [stringpath(path) for path in pdirs]

    for pointer, sd, d in zip(pointers, sdirs, dirs):
        yield prefix + pointer + d.filename
        if S_ISDIR(d.st_mode):
            extension = branch if pointer == tee else space
            yield from tree_sftp(sftp, sd, prefix=prefix + extension)

import pysftp
with pysftp.Connection(HOSTNAME, USERNAME, PASSWORD) as sftp:
    for file in tree(sftp):
        print(file)