Serialize and Deserialize Binary Tree

'''
Logic:
step1: We will traverse the tree levelwise using BFS in serialize function and store in string.
while stroing tree in string,we will give one space between every node and "null" for NULL node.

step2: In deserialize function,we will store the nodes into vector of string and pass to fun.
fun will traverse the tree levelwise using BFS and push the elements into tree.
'''

from collections import deque
class Codec:
    def __init__(self):
        self.i=0
    def get_next_num(self,data):
        cur=''
        while data[self.i]!=' ':
            cur+=data[self.i]
            self.i+=1
        self.i+=1
        if cur=='None':
            return None
        return int(cur)

    def serialize(self, root):
        if root==None:
            return ''
        ans=''
        ans+=(str(root.val)+' ')
        q=deque()
        q.append(root)
        while len(q)>0:
            k=len(q)
            for i in range(k):
                temp=q.popleft()
                if temp.left:
                    ans+=(str(temp.left.val)+' ')
                    q.append(temp.left)
                else:
                    ans+='None '

                if temp.right:
                    ans+=(str(temp.right.val)+' ')
                    q.append(temp.right)
                else:
                    ans+='None '
        return ans



    def deserialize(self, data):
        print(data)
        if data=='':
            return None
        x=self.get_next_num(data)
        root=TreeNode(x)
        q=deque()
        q.append(root)
        while len(q)>0:
            k=len(q)
            print("The k is : ",k)
            for i in range(k):
                temp=q.popleft()
                x=self.get_next_num(data)
                print(f"The temp values is: {temp.val} and x is {x}")
                if x!=None:
                    temp.left=TreeNode(x)
                    q.append(temp.left )

                x=self.get_next_num(data)
                print(f"The temp values is: {temp.val} and x is {x}")
                if x!=None:
                    temp.right=TreeNode(x)
                    q.append(temp.right)

        return root