class Node:

def __init__(self, name):

self.name = name

self.children = []

def add_node(self, child):

self.children.append(child)

def iter_tree(self, depth_first=False):

nodes = [(self, None, 0)]

while nodes:

if depth_first:

node, parent, n = nodes.pop()

children = reversed(node.children)

else:

node, parent, n = nodes.pop(0)

children = node.children

yield node, parent, n

for child in children:

nodes.append((child, node, n+1))

def print_tree(self):

rows = [[]]

for node, parent, n in self.iter_tree(depth_first=True):

node.parent = parent

if n >= len(rows):

l = len(rows[n - 1]) - 1

rows.append([None] * l)

rows[n].append(node)

for row in rows[:n]:

while len(row) < len(rows[n]):

row.append(None)

for row in rows[n+1:]:

while len(row) < len(rows[n]) - 1:

row.append(None)

for y, row in enumerate(rows):

if y:

line = ''

spaces = 0

for x, node in enumerate(row):

if x:

spaces += 1

if node and node.parent is rows[y-1][x]:

line += ' ' * spaces + '|'

spaces = 0

else:

spaces += 1

print(line)

line = ''

spaces = 0

last = None

for x, node in enumerate(row):

if x:

spaces += 1

if node:

char = '-' if last and last.parent is node.parent else ' '

line += char * spaces + node.name

spaces = 0

last = node

else:

spaces += 1

print(line)