How about solving the actual problem instead of trying to convert it?
I don't know python, but if I understand this part of the code correctly:
n = int(input())
numbers = [int(i) for i in input().split()]
edges = 
nodes = [Node(count) for count in range(n + 1)]
for i in range(n):
nodes[i] = Node(i)
for i in range(1, n):
(nodes[numbers[i - 1]]).children.append(nodes[i + 1])
edges.append((numbers[i - 1], i + 1))
Then n is some arbitrary integer read from input, numbers is an array with a length determined by different
input, and the for loop references elements of that array with indexes 0 through n-1. Do these elements even exist?
Also, the function setNumOfLeaves appears to be doing too many things at the same time: it's used both for initializing the branches/leaves, and for querying the children. Maybe it would help to separate that functionality.