Write a python program to implement a stack using a list data-structure. Class 12 computer science 083 new Term II practical Program
def isempty(stk):
if stk==[]:
return True
else:
return False
def push(stk,item):
stk.append(item)
top=len(stk)-1
def pop(stk):
if isempty(stk):
return "underflow"
else:
item=stk.pop()
if len(stk)==0:
top=None
else:
top=len(stk)-1
return item
def peek(stk):
if isempty(stk):
return "underflow"
else:
top=len(stk)-1
return stk[top]
def display(stk):
if isempty(stk):
print('stack is empty')
else:
top=len(stk)-1
print(stk[top],'<-top')
for i in range(top-1,-1,-1):
print(stk[i])
#Driver Code
def main():
stk=[]
top=None
while True:
print('''stack operation
1.push
2.pop
3.peek
4.display
5.exit''')
choice=int (input('enter choice:'))
if choice==1:
item=int(input('enter item:'))
push(stk,item)
elif choice==2:
item=pop(stk)
if item=="underflow":
print('stack is underflow')
else:
print('poped')
elif choice==3:
item=peek(stk)
if item=="underflow":
print('stack is underflow')
else:
print('top most item is:',item)
elif choice==4:
display(stk)
elif choice==5:
break
else:
print('invalid')
exit()
main()
Sample Source code snap
