Find maximum in stack in O(1) without using additional stack in Python

# Python3 implementation of the approach
class Block:

    # A block has two elements
    # as components (i.e. value and localMax)
    def __init__(self, value, localMax):
        self.value = value
        self.localMax = localMax


class Stack:
    def __init__(self, size):

        # Setting size of stack and
        # initial value of top
        self.stack = [None] * size
        self.size = size
        self.top = -1

    # Function to push an element
    # to the stack
    def push(self, value):

        # Don't allow pushing elements
        # if stack is full
        if self.top == self.size - 1:
            print("Stack is full")
        else:
            self.top += 1

            # If the inserted element is the first element
            # then it is the maximum element, since no other
            # elements is in the stack, so the localMax
            # of the first element is the element itself
            if self.top == 0:
                self.stack[self.top] = Block(value, value)

            else:

                # If the newly pushed element is less
                # than the localMax of element below it,
                # Then the over all maximum doesn't change
                # and hence, the localMax of the newly inserted
                # element is same as element below it
                if self.stack[self.top - 1].localMax > value:
                    self.stack[self.top] = Block(
                        value, self.stack[self.top - 1].localMax)

                # Newly inserted element is greater than
                # the localMax below it, hence the localMax
                # of new element is the element itself
                else:
                    self.stack
                    self.stack[self.top] = Block(value, value)

            print(value, "inserted in the stack")

    # Function to remove an element
    # from the top of the stack
    def pop(self):

        # If stack is empty
        if self.top == -1:
            print("Stack is empty")

        # Remove the element if the stack
        # is not empty
        else:
            self.top -= 1
            print("Element popped")

    # Function to find the maximum
    # element from the stack
    def getMax(self):

        # If stack is empty
        if self.top == -1:
            print("Stack is empty")
        else:

            # The overall maximum is the local maximum
            # of the top element
            print("Maximum value in the stack:",
                  self.stack[self.top].localMax)

# Driver code


# Create stack of size 5
stack = Stack(5)
stack.push(2)
stack.getMax()
stack.push(6)
stack.getMax()
stack.pop()
stack.getMax()