Write a program using a queue (array_queue.py below) class and stack (array_stack.py below) that contains a function isPalindrome(phrase) to validate whether an input phrase is a palindrome.

Array_queue.py

from exceptions import Empty

class ArrayQueue:

"""FIFO queue implementation using a Python list as underlying storage."""

DEFAULT_CAPACITY = 10 # moderate capacity for all new queues

def __init__(self):

"""Create an empty queue."""

self._data = [None] * ArrayQueue.DEFAULT_CAPACITY

self._size = 0

self._front = 0

def __len__(self):

"""Return the number of elements in the queue."""

return self._size

def is_empty(self):

"""Return True if the queue is empty."""

return self._size == 0

def first(self):

"""Return (but do not remove) the element at the front of the queue.

Raise Empty exception if the queue is empty.

"""

if self.is_empty():

raise Empty('Queue is empty')

return self._data[self._front]

def dequeue(self):

"""Remove and return the first element of the queue (i.e., FIFO).

Raise Empty exception if the queue is empty.

"""

if self.is_empty():

raise Empty('Queue is empty')

answer = self._data[self._front]

self._data[self._front] = None # help garbage collection

self._front = (self._front + 1) % len(self._data)

self._size -= 1

return answer

def enqueue(self, e):

"""Add an element to the back of queue."""

if self._size == len(self._data):

self._resize(2 * len(self.data)) # double the array size

avail = (self._front + self._size) % len(self._data)

self._data[avail] = e

self._size += 1

def _resize(self, cap): # we assume cap >= len(self)

"""Resize to a new list of capacity >= len(self)."""

old = self._data # keep track of existing list

self._data = [None] * cap # allocate list with new capacity

walk = self._front

for k in range(self._size): # only consider existing elements

self._data[k] = old[walk] # intentionally shift indices

walk = (1 + walk) % len(old) # use old size as modulus

self._front = 0 # front has been realigned

array_stack.py

class ArrayStack:

"""LIFO Stack implementation using a Python list as underlying storage."""

def __init__(self):

"""Create an empty stack."""

self._data = [] # nonpublic list instance

def __len__(self):

"""Return the number of elements in the stack."""

return len(self._data)

def is_empty(self):

"""Return True if the stack is empty."""

return len(self._data) == 0

def push(self, e):

"""Add element e to the top of the stack."""

self._data.append(e) # new item stored at end of list

def top(self):

"""Return (but do not remove) the element at the top of the stack.

Raise Empty exception if the stack is empty.

"""

if self.is_empty():

#raise Empty('Stack is empty')

print('Stack is empty')

return self._data[-1] # the last item in the list

def pop(self):

"""Remove and return the element from the top of the stack (i.e., LIFO).

Raise Empty exception if the stack is empty.

"""

if self.is_empty():

#raise Empty('Stack is empty')

print('Stack is empty')

return self._data.pop() # remove last item from list

def transfer(self,T):

while not self.is_empty():

temp = self.pop()

T.push(temp)

def main():

S = ArrayStack()

print(S.push(1))

print(S.top())

print(S.push(2))

print(S.top())

S.push(3)

S.push(4)

print(S.is_empty())

T = ArrayStack()

print(T.is_empty())

S.transfer(T)

print(T.is_empty())

print str(S)

main()

python

include docstring

comment code

typed please and show run screen