python: stack

class stack:
        def __init__(self, size=10):
            self.size = size
            self.array = [None]*self.size
            self.i = -1
            
        def push(self, element):
            if self.isFull():
                raise Exception("Array out of bound")
            self.i += 1
            self.array[self.i] = element
        
        def pop(self):
            if self.isEmpty():
                raise Exception("Array out of bound")
            self.i -= 1
            return self.array[self.i+1]
        
        def peek(self):
            return self.array[self.i]
        
        def isEmpty(self):
            return self.i <= -1
        
        def isFull(self):
            return self.i >= self.size-1
        
        def clear(self):
            self.array = [None for _ in  range(self.size)]
            self.i = -1