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stack.py
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stack.py
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class Stack(object):
def __init__(self):
self.stack = []
def is_empty(self):
if self.stack:
return False
return True
def push(self, data):
self.stack.append(data)
def pop(self):
deleted = None
if self.is_empty():
print('Stack is empty!')
else:
deleted = self.stack.pop()
return deleted
class Node(object):
def __init__(self, value, next_pointer=None):
self.value = value
self.next = next_pointer
class StackLinkedList(object):
def __init__(self):
self.head = None
def is_empty(self):
if self.head:
return False
return True
def push(self, data):
node = Node(data)
node.next = self.head
self.head = node
def pop(self):
deleted = None
if self.is_empty():
print('Stack is empty!')
else:
deleted = self.head.value
self.head = self.head.next
return deleted