637. Average of Levels in Binary Tree

class Solution(object):
    def averageOfLevels(self, root):
        list1=[]
        queue=[root,None]
        l=2
        while l!=1:
            if queue[0]==None:
                queue.pop(0)
                list1.append("#")
                queue.append(None)
            list1.append(queue[0].val)
            l-=1
            if queue[0].left!=None:
                queue.append(queue[0].left)
                l+=1
            if queue[0].right!=None:
                queue.append(queue[0].right)
                l+=1
            queue.pop(0)
        sum1=0
        c=0
        queue=[]
        print(list1)
        for i in list1:
            if i!="#":
                sum1+=i
                c+=1
            else:
                queue.append(float(sum1)/float(c))
                sum1=0
                c=0
        queue.append(float(sum1)/float(c))
                
        return queue