[Stack Implementation in Python]

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)

[Reverse String using Stack]

from stack import *
def revString(String):
index=0
s=Stack()
while index < len(String):
symbol=String[index]
print symbol
s.push(symbol)
index=index + 1
revstring=""

while not s.isEmpty():
revstring=revstring + str(s.pop())
return revstring

print (revString('parag'))

[Parenthesis matching using Stack]

from stack import * 

def parChecker(symbolString):

s=Stack()

balanced = True

index=0

while index < len (symbolString) and balanced:

symbol = symbolString[index]

print symbol

if symbol in "([{" :

s.push(symbol)

else:

if s.isEmpty():

balanced=False

else:

top=s.pop()

if not matches(top,symbol):

balanced=False

index=index + 1

if balanced and s.isEmpty():

return True

else:

return False

def matches(open,close):

opens="([ {"

close =")]}"

return opens.index(open)==close.index(close)

print(parChecker('[{([][])}()}'))

[ Decimal to Binary Conversion ]

from stack import *

def divby2(number):

s=Stack()

while number > 0:

remainder=number % 2

s.push(remainder)

number = number // 2

binString=""

while not s.isEmpty():

binString=binString + str(s.pop())

return binString

print (divby2(10))