Running Median of Data Stream

Given an input stream of n integers the task is to insert integers to stream and print the median of the new stream formed by each insertion of x to the stream.

class MaxHeap(object):
    def __init__(self):
        self.heap_list = [0]
        self.current_size = 0

    def empty(self):
        return (self.current_size==0)
    def perc_up(self,i):
        while i//2>0:
            if self.heap_list[i] > self.heap_list[i//2]:
                self.heap_list[i],self.heap_list[i//2] = self.heap_list[i//2],self.heap_list[i]
            i = i//2

    def insert(self,val):
        self.heap_list.append(val)
        self.current_size+=1
        self.perc_up(self.current_size)

    def get_child(self,i):
        if 2*i+1 > self.current_size:
            return 2*i
        else:
            if self.heap_list[2*i] > self.heap_list[2*i+1]:
                return 2*i
            else:
                return 2*i+1

    def perc_down(self,i):
        while 2*i<=self.current_size:
            child_id = self.get_child(i)
            if self.heap_list[child_id] > self.heap_list[i]:
                self.heap_list[child_id],self.heap_list[i] = self.heap_list[i],self.heap_list[child_id]

            i = child_id

    def peek(self):
        if self.current_size:
            return self.heap_list[1]
        else:
            return None

    def del_max(self):
        if self.current_size:
            max_val = self.heap_list[1]
            self.heap_list[1] = self.heap_list[-1]
            self.heap_list.pop()
            self.current_size-=1
            self.perc_down(1)
            return max_val
        else:
            return None

class MinHeap(object):
    def __init__(self):
        self.heap_list = [0]
        self.current_size = 0

    def empty(self):
        return (self.current_size==0)

    def peek(self):
        if self.current_size:
            return self.heap_list[1]
        else:
            return None

    def perc_up(self,i):
        while i//2>0:
            if self.heap_list[i] < self.heap_list[i//2]:
                self.heap_list[i],self.heap_list[i//2] = self.heap_list[i//2],self.heap_list[i]
            i = i//2

    def insert(self,val):
        self.heap_list.append(val)
        self.current_size+=1
        self.perc_up(self.current_size)

    def get_child(self,i):
        if 2*i+1>self.current_size:
            return 2*i
        else:
            if self.heap_list[2*i] < self.heap_list[2*i+1]:
                return 2*i
            else:
                return 2*i+1

    def perc_down(self,i):
        while 2*i<=self.current_size:
            child_id = self.get_child(i)
            if self.heap_list[child_id] < self.heap_list[i]:
                slef.heap_list[child_id],self.heap_list[i] = self.heap_list[i],self.heap_list[child_id]

            i = child_id

    def del_min(self):
        if self.current_size:
            min_val = self.heap_list[1]
            self.heap_list[1] = self.heap_list[-1]
            self.heap_list.pop()
            self.current_size -=1
            self.perc_down(1)
            return min_val
        else:
            return None

def running_median(data):
    left_max_heap = MaxHeap()
    right_min_heap = MinHeap()
    for val in data:
        if left_max_heap.empty() or left_max_heap.peek() > val:
            left_max_heap.insert(val)
        else:
            right_min_heap.insert(val)
        if abs(left_max_heap.current_size - right_min_heap.current_size )>1:
            if left_max_heap.current_size > right_min_heap.current_size:
                left_max = left_max_heap.del_max()
                right_min_heap.insert(left_max)
            else:
                right_min = right_min_heap.del_min()
                left_max_heap.insert(right_min)
        if right_min_heap.current_size == left_max_heap.current_size:
            print (right_min_heap.peek()+left_max_heap.peek())/2.0
        else:
            median = right_min_heap.peek() if right_min_heap.current_size > left_max_heap.current_size else left_max_heap.peek()
            print median