class Node:
    emty_path = '    '
    parent_path = '│   '
    node_middle = '├─{}─'
    node_last = '└─{}─'

    def __init__(self, attribute):
        self.attribute = attribute
        self.children = {}

    def add_branch(self, attribute, subtree):
        self.children[attribute] = subtree

    def __eq__(self, other):
        return self.attribute == other

    def __repr__(self):
        if self.children:
            return f'A:{self.attribute+1}'  # 1-index for easy reading
        return f'Class: {self.attribute}'

    def __str__(self, level=0, parent_levels=[], identifier='', last=False):
        """ Hard to read, but print looks real nice."""
        ret = [self.emty_path]*(level)

        for i in parent_levels:
            ret[i] = self.parent_path

        prefix = ''
        if level > 0:
            if last:
                prefix = self.node_last.format(str(identifier))
            else:
                prefix = self.node_middle.format(str(identifier))

        ret = ''.join(ret[:-1]) + prefix + repr(self) + '\n'

        if self.children:
            parent_levels.append(level)
            for i, (key, child) in enumerate(self.children.items(), start=1):
                if i == len(self.children):  # Last child for node
                    parent_levels.remove(level)
                    ret += child.__str__(level+1, parent_levels,
                                         identifier=key, last=True)
                else:
                    ret += child.__str__(level+1, parent_levels,
                                         identifier=key)
        return ret