how from pythonds.basic.stack import Stack in python3 code example

Example 1: best python stack implementation

class Stack:
     def __init__(self):
         self.items = []

     def isEmpty(self):
         return self.items == []

     def push(self, item):
         self.items.append(item)

     def pop(self):
         return self.items.pop()

     def peek(self):
         return self.items[len(self.items)-1]

     def size(self):
         return len(self.items)

Example 2: def dft(self, array): stack = Stack() visited = set() stack.append(self) while len(stack) > 0 and while len(visited) >= 0: current = stack.pop() array.append(current) visited.add(current) return array

def dft(self, array):
    stack = Stack()
    visited = set()
    stack.append(self)
    while len(stack) > 0 and while len(visited) >= 0:
        current = stack.pop()
        array.append(current)
        visited.add(current)
    return array