def draw_tree(self, tree, root):
self.counterNull = 0
self.counterNodes = 0
B = self.copy_tree(getattr(tree, root))
x, y, z = self.compute_position(B)
listNodes = self.encode_nodes(B)
listStr = self.encode_edges(B)
src = Source('graph "Arbol" { rankdir=TB; ' + listNodes +
' node[shape=circle] ' + listStr + ' }')
src.engine = "neato"
src.render('lista.gv', view=True)
display(SVG(src.pipe(format='svg')))
