Huffman Code

class binaryTreeNode():
    def __init__(self,data=None):
        self.data = data
        self.left = None
        self.right = None

    def returnData(self):
        return self.data

    def printBinaryTree(self,s = '---'):
        if self.data:
            print(s+self.data)
            s = '   ' + s
            if self.left:
                self.left.printBinaryTree(s)
            if self.right:
                self.right.printBinaryTree(s)

def huffmanCode(dictionary):
    current_nodes = sorted([[binaryTreeNode(item[0]),item[1]] for item 
                                in dictionary.items()],key=lambda x: x[1])
    while len(current_nodes) > 1:
        newNode = binaryTreeNode(current_nodes[0][0].data+current_nodes[1][0].data)
        newNode.left = current_nodes[1][0]
        newNode.right = current_nodes[0][0]
        newSum = current_nodes[0][1] + current_nodes[1][1]
        current_nodes = sorted([[newNode,newSum]] + current_nodes[2:],key=lambda x: x[1])
    return current_nodes[0][0]

def convertToBinary(tree,c,string=''):
    if tree.left == None and tree.right == None:
        return c+': '+string
    else:
        if c in tree.left.data:
            return convertToBinary(tree.left,c,string+'0')
        else:
            return convertToBinary(tree.right,c,string+'1')

d = {'A':0.08,'B':0.1,'C':0.12,'D':0.15,'E':0.20,'F':0.35}

huff = huffmanCode(d)

huff.printBinaryTree()

for key in sorted(d.keys()):
    print(convertToBinary(huff,key))