heritance (based on 8.38) You MUST use inheritance for this problem. A stack is a sequence container type that, like a queue, supports very restrictive access methods: all insertions and removals are from one end of the stack, typically referred to as the top of the stack.  A stack is often referred to as a last-in first-out (LIFO) container because the last item inserted is the first removed.  Implement a Stack class using Note that this means you may be able to inherit some of the methods below.  Which ones?  (Try not writing those and see if it works!) Constructor/_init__ - Can construct either an empty stack, or initialized with a list of items, the first item is at the bottom, the last is at the top. push() – take an item as input and push it on the top of the stack pop() – remove and return the item at the top of the stack isEmpty() – returns True if the stack is empty, False otherwise [] – return the item at a given location, [0] is at the bottom

Use Python for this question. Also please comment what each line of code means for this question as well:

1. Inheritance (based on 8.38) You MUST use inheritance for this problem. A stack is a sequence container type that, like a queue, supports very restrictive access methods: all insertions and removals are from one end of the stack, typically referred to as the top of the stack.  A stack is often referred to as a last-in first-out (LIFO) container because the last item inserted is the first removed.  Implement a Stack class using Note that this means you may be able to inherit some of the methods below.  Which ones?  (Try not writing those and see if it works!)
   1. Constructor/_init__ - Can construct either an empty stack, or initialized with a list of items, the first item is at the bottom, the last is at the top.
   2. push() – take an item as input and push it on the top of the stack
   3. pop() – remove and return the item at the top of the stack
   4. isEmpty() – returns True if the stack is empty, False otherwise
   5. [] – return the item at a given location, [0] is at the bottom of the stack
   6. len() – return length of the stack

Output for this problem:

##### Stack #####

>>> s = Stack()
>>> len( vars(s)) # really inheriting? failure on this test means Stack is probably not properly inheriting
0
>>> isinstance(s,list) # inheriting?
True

>>> s = Stack()
>>> s.push('apple')
>>> s
Stack(['apple'])
>>> s.push('pear')
>>> s.push('kiwi')
>>> s
Stack(['apple', 'pear', 'kiwi'])
>>> top = s.pop()
>>> top
'kiwi'
>>> s
Stack(['apple', 'pear'])
>>> len(s)
2
>>> s.isEmpty()
False
>>> s.pop()
'pear'
>>> s.pop()
'apple'
>>> s.isEmpty()
True
>>> s = Stack(['apple', 'pear', 'kiwi'])
>>> s = Stack(['apple', 'pear', 'kiwi'])
>>> s[0]
'apple'
>>>

if you receive an error on s2 then you are probably not calling the list
constructor init.

>>> s = Stack()
>>> s.push('apple')
>>> s
Stack(['apple'])
>>> s2 = Stack()
>>> s2.push('pear')
>>> s2 # if this fails - see the TEST file for explanation
Stack(['pear'])

check that the Stack is really inheriting from list

>>> s = Stack()
>>> isinstance(s, list)
True
>>> len( vars(s) )==0
True