class Stack():
def __init__(self, list = []):
self._stack = list
def push(self, item):
if(hasattr(item, "__getitem__")):
self._stack.extend(item)
else:
self._stack.append(item)
def isEmpty(self):
return not self._stack
def pop(self):
if(self.isEmpty()):
return None
return self._stack.pop()
def peek(self):
if(self.isEmpty()):
return None
return self._stack[-1]
def size(self):
return len(self._stack)
from collections import deque
the_stack = deque()
# this function can serve as push
the_stack.append("data")
print(the_stack.pop()) # -> data
# Check out the documents for more features coming when using that dedicated
# builtin.
# About deque: Deques are a generalization of stacks and queues
# (the name is pronounced “deck” and is short for “double-ended queue”).
# Deques support thread-safe, memory efficient appends and pops from either
# side of the deque with approximately the same O(1) performance in either
# direction.
# Special note: I've coded different types of code to explain the stack.
# So, you can use the code that will help you understand. Thank you. Happy coding.
# Stack:
# Stack main structure = Last in First Out..
# 1st system easy code and Main Code:
class Stack:
def __init__(self):
self.items = []
# items check the None:
def is_empty(self):
if self.items == []:
return True
else:
return False
# item append:
def push(self,item):
self.items.append(item)
# item delete or pop:
def delete(self):
return self.items.pop()
if __name__ == "__main__":
s = Stack()
s.push(2)
s.push(3)
s.push(4)
while not s.is_empty():
item = s.delete()
print(item)
#Programe Finished.
# Stack details system code...
'''
stack = []
# append() function to push
# element in the stack
stack.append('a')
stack.append('b')
stack.append('c')
print('Initial stack')
print(stack)
# pop() function to pop
# element from stack in
# LIFO order
print('
Elements poped from stack:')
print(stack.pop())
print(stack.pop())
print(stack.pop())
print('
Stack after elements are popped:')
print(stack)
# uncommenting print(stack.pop())
# will cause an IndexError
# as the stack is now empty
'''
# Stack details system: But, used not definition and class:
# just for understand.
'''
li = []
for _ in range(int(input())):
print("Last in append:")
li.append(int(input()))
while len(li)>1:
print(li)
li.pop()
print("First out = ",li)
print("First out = ",li)
'''
# Stack Example and 2nd system:
'''
class My_stack():
def __init__(self):
self.data = []
def my_push(self, x):
return (self.data.append(x))
def my_pop(self):
return (self.data.pop())
def my_peak(self):
return (self.data[-1])
def my_contains(self, x):
return (self.data.count(x))
def my_show_all(self):
return (self.data)
arrStack = My_stack()
arrStack.my_push(1)
arrStack.my_push(2)
arrStack.my_push(1)
arrStack.my_push(3)
print(arrStack.my_show_all())
arrStack.my_pop()
print(arrStack.my_show_all())
print(arrStack.my_contains(1))
'''
# Stack 3rd system:
# Stack main structure = Last in First Out..
'''
class Stack:
def __init__(self):
self.Stack = []
self.size = 0
def DataAdd(self, new_data):
self.Stack.append(new_data)
self.size += 1
def outElement(self):
self.size -= 1
return self.Stack.pop()
def isEmptySTack(self):
if self.size == 0:
return "Stack is Empty!"
else:
return "Stack is Full"
def print_Stack(self):
return self.Stack
def firstData(self):
return self.Stack[0]
def LastData(self):
return self.Stack[-1]
# Reversing korar jonno
def ReversedStack(self):
return self.Stack[::-1]
if __name__ == "__main__":
op = Stack()
# add data
op.DataAdd('0. English')
op.DataAdd("1. Bangla")
op.DataAdd("2. Math")
op.DataAdd("3. Islam")
op.DataAdd("4. Hindi")
print("Before Stack:", op.print_Stack())
print("Before Stack Size", op.size)
print()
# remove Data
op.outElement()
op.outElement() # 2 element remove
print("After Stack", op.print_Stack())
print("After Stack Size", op.size)
# Stack Size
print(op.size)
# Reversed Stack
print("Reversed Stack", op.ReversedStack())
# Stack First Data
print("This is Stack First Element", op.firstData())
print("This is Stack Last Element", op.LastData())
'''
# Stuck Example to 4th system...
'''
class BBPI:
def __init__(self, name, roll, id):
self.Name = name
self.Roll = roll
self.Id = id
def CMT(self):
return self.Name, self.Roll, self.Id
def EMT(self):
return self.Name, self.Roll, self.Id
def RAT(self):
pass
class CPI(BBPI):
def emt(self):
return self.Name, self.Roll, self.Id
# Driver Code
if _name_ == '_main_':
op = BBPI("Murad", 165090, 677312838)
op1 = BBPI("kamal", 214231, 124535221)
print(op.CMT())
print(op1.EMT())
print("CPI")
o = CPI("a", 121, 11)
print(o.emt())
'''
# Stack 5th system example and easy system to code:
'''
class Stack:
def __init__(self):
self.list = []
def emty_list(self):
if self.list == []:
return True
else:
return False
def data_append(self,data):
self.list.append(data)
def data_delete(self):
return self.list.pop()
s = Stack()
s.data_append(3)
s.data_append(4)
s.data_append(5)
while not s.emty_list():
print(s.data_delete())
'''
# Stack is Last In First Out data structure
stack = []
stack.append(1)
stack.append(2)
stack.append(3) # 3 is top element of stack at this point
print(stack) # [1, 2, 3]
top_element = stack.pop()
print(top_element) # 3
print(stack.pop()) # 2
print(stack.pop()) # 1
print("Stack after being emptied: ")
print(stack) # []
"""Stack
Stack is a Last In - First Out (LIFO) data structure, much like stacking.
- The below is a simple class implementation of it
Check out the source for more info!
"""
class Stk:
def __init__(self):
self.s = [] # empty lst
def push(self, data): # Insert new data
self.s.append(data)
def pop(self): # Remove latest data
if self.s:
return self.s.pop()
return "Empty!"
def peek(self): # See latest data
if self.s:
return self.s[-1]
return "Empty!"
def size(self): # find size
return len(self.s)
def display(self):
return self.s
# Test
from random import randrange
def Stk_Test(stk):
# Create random list
lst = [randrange(10, 100) for _ in range(10)]
print(f"List: {lst}")
# Create Empty Stack
S = stk()
print(f"Stk: {S.display()}",
f"Size: {S.size()}",
f"Top: {S.peek()}",
sep = " | ", end = "
")
# Put items into stack
for item in lst:
S.push(item)
print(f"Top: {S.peek()}",
f"Stk: {S.display()}",
sep = " | ", end = "
")
# Remove items from stack
for _ in range(len(lst)):
print(f"Popped: {S.pop()}",
f"Top: {S.peek()}",
f"Size: {S.size()}",
f"Stk: {S.display()}",
sep = " | ")
Stk_Test(Stk)