Lecture "Organising information: ordered structures", exercise 2

[essepuntato]

Consider to have a stack obtained by processing, one by one, the elements included in the list of the first exercise, i.e. my_stack = deque(["Draco", "Harry", "Hermione", "Ron", "Severus"]). Describe the status of my_stack after the execution of each of the following operations: my_stack.pop(), my_stack.pop(), my_stack.append("Voldemort").

[giorgimariachiara]

The status of my_stack at the and of all the operations is: Draco, Harry, Hermione, Voldemort

[elizastuglik]

The status of the my_stack Will be: Draco, Harry, Hermione, Voldemort.

[sotarega]

my_stack = deque(["Draco", "Harry", "Hermione", "Ron", "Severus"])
print(my_stack)
['Draco', 'Harry', 'Hermione', 'Ron', 'Severus']

my_stack.pop()
print(my_stack)
['Draco', 'Harry', 'Hermione', 'Ron']

my_stack.pop()
print(my_stack)
['Draco', 'Harry', 'Hermione']

my_stack.append("Voldemort")
print(my_stack)
['Draco', 'Harry', 'Hermione', 'Voldemort']

[tommasobattisti]

my_stack will contain the following items:
"Draco", "Harry", "Hermione", "Voldemort".

from collections import deque
my_stack = deque(["Draco", "Harry", "Hermione", "Ron", "Severus"])
my_stack.pop()
my_stack.pop()
my_stack.append("Voldemort")
print(my_stack)

deque(['Draco', 'Harry', 'Hermione', 'Voldemort'])

[ManueleVeggi]

The two commands my_stack.pop() will remove the last elements, which are 'Ron' and 'Severus. The command extend will add the 'Voldemort'at the end of the stack. The result is hence:
['Draco', 'Harry', 'Hermione', 'Voldemort']

[OrsolaMBorrini]

my_stack = deque(["Draco", "Harry", "Hermione", "Ron", "Severus"])
my_stack.pop()
#The status of my_stack is now ["Draco", "Harry", "Hermione", "Ron"]
my_stack.pop()
#The status of my_stack is now ["Draco", "Harry", "Hermione"]
my_stack.append("Voldemort")
#The status of my_stack is now ["Draco", "Harry", "Hermione", "Voldemort"]

[CarmenSantaniello]

my_stack = deque(["Draco", "Harry", "Hermione", "Ron", "Severus"])
my_stack.pop()

deque(['Draco', 'Harry', 'Hermione', 'Ron'])

my_stack = deque(["Draco", "Harry", "Hermione", "Ron", "Severus"])
my_stack.pop()
my_stack.pop()

deque(['Draco', 'Harry', 'Hermione'])

my_stack = deque(["Draco", "Harry", "Hermione", "Ron", "Severus"])
my_stack.pop()
my_stack.pop()
my_stack.append("Voldemort")

deque(['Draco', 'Harry', 'Hermione', 'Voldemort'])

[ghasempouri1984]

from collections import deque

my_stack = deque(["Draco", "Harry", "Hermione", "Ron", "Severus"])
print(my_stack)

my_stack.pop()
print(my_stack)

my_stack.pop()
print(my_stack)

my_stack.append("Voldemort")
print(my_stack)

[angstigone]

my_stack = deque(["Draco", "Harry", "Hermione", "Ron", "Severus"])

my_stack.pop()

stack becomes (["Draco", "Harry", "Hermione", "Ron"]).

my_stack.pop()

stack becomes (["Draco", "Harry", "Hermione"]).

my_stack.append(Voldemort).

stack becomes (["Draco", "Harry", "Hermione", "Voldemort"]).

[MaddaGh]

deque(["Draco", "Harry", "Hermione", "Voldemort"])

[NoraPs]

from collections import deque
from typing import Deque

my_stack = deque (["Draco", "Harry", "Hermione", "Ron", "Severus"])
my_stack.pop()
my_stack.pop()
my_stack.append("Voldemort")
print (my_stack)

deque(['Draco', 'Harry', 'Hermione', 'Voldemort'])

[francescabudel]

my_stack = deque (["Draco", "Harry","Hermione", "Ron", "Severus"])
my_stack.pop() 
my_stack.pop()
my_stack.append("Voldemort")

print(my_stack)
deque(['Draco', 'Harry', 'Hermione', 'Voldemort'])

[sterenz]

from collections import deque

my_stack = deque(["Draco", "Harry", "Hermione", "Ron", "Severus"])
my_stack.pop() # remove the rightmost item
print(my_stack)
deque(['Draco', 'Harry', 'Hermione', 'Ron'])

my_stack.pop() # remove the rightmost item
print(my_stack)
deque(['Draco', 'Harry', 'Hermione'])

my_stack.append("Voldemort") # add a new entry to the right side
print(my_stack)
deque(['Draco', 'Harry', 'Hermione', 'Voldemort'])

[RebeccaJillianBeattie]

Visualising it like a stack:

my_stack
Severus
Ron
Hermione
Harry
Draco
["Draco", "Harry", "Hermione", "Ron", "Severus"]

my_stack.pop()
Ron
Hermione
Harry
Draco
["Draco", "Harry", "Hermione", "Ron"]

my_stack.pop()
Hermione
Harry
Draco
["Draco", "Harry", "Hermione"]

my_stack.append("Voldemort")
Voldemort
Hermione
Harry
Draco
["Draco", "Harry", "Hermione", "Voldemort"]

[olgagolgan]

[SaraVell1]

[AnastasiyaSopyryaeva]

INPUT
from typing import Deque
my_stack = Deque(["Draco", "Harry", "Hermione", "Ron", "Severus"])
print(my_stack)

my_stack.pop()
print(my_stack)

my_stack.pop()
print(my_stack)

my_stack.append("Voldemort")
print(my_stack)

OUTPUT
deque(['Draco', 'Harry', 'Hermione', 'Ron', 'Severus'])
deque(['Draco', 'Harry', 'Hermione', 'Ron'])
deque(['Draco', 'Harry', 'Hermione'])
deque(['Draco', 'Harry', 'Hermione', 'Voldemort'])

[martasoricetti]

The method .pop() removes the item on the top of the stack, that is the last item added in the stack ->

my_stack.pop()
print(my_stack)
deque(["Draco", "Harry", "Hermione", "Ron"])

my_stack.pop()
print(my_stack)
deque(["Draco", "Harry", "Hermione"])

The method .append() allows one to add an item on the top of the stack ->

my_stack.append("Voldemort")
print(my_stack)
deque(["Draco", "Harry", "Hermione", "Voldemort"])

[chloeppd]

[AmeliaLamargese]

my_stack = deque(["Draco", "Harry", "Hermione", "Ron", "Severus"]) 

with the execution of my_stack.pop() function, the last item will be removed,
in this case "Severus" will be deleted and returned
my_stack = ["Draco", "Harry", "Hermione", "Ron"]

after my_stack.pop() function, the last item will be removed,
in this case "Ron" will be deleted and returned
my_stack = ["Draco", "Harry", "Hermione"]

with my_stack.append("Voldemort") , "Voldemort" will be added to the stack as the last item
my_stack = ["Draco", "Harry", "Hermione", "Voldemort"]

[ManuSrivastava1]

At the top of our stack is Severus and Draco is at the bottom. Following the FILO principle.
The first pop command will remove from the top - Severus.
The second pop command will remove from the top - rounds
The append command will add to the top - Voldermort

Giving us the final stack as -
deque['Draco','Harry','Hermoine','Voldermort']

[sarabecchi]

The status of my_stack after the execution of those operations is:

deque(['Draco', 'Harry', 'Hermione', 'Voldemort'])

[Postitisnt]

deque(['Draco', 'Harry', 'Hermione', 'Voldemort'])

[sanyuezoe]

from collections import deque
my_stack = deque(["Draco", "Harry", "Hermione", "Ron", "Severus"])
my_stack.pop()
print(my_stack)

deque(['Draco', 'Harry', 'Hermione', 'Ron'])

my_stack.pop()
print(my_stack)

deque(['Draco', 'Harry', 'Hermione'])

my_stack.append("Voldemort")
print(my_stack)

deque(['Draco', 'Harry', 'Hermione', 'Voldemort'])

[teragramgius]

my_stack = deque(["Draco", "Harry", "Hermione", "Ron", "Severus"]) 
#a stack is characterized by Last In First Out strategy for adding and removing items. So the process is at it follows.

#I'll go two times with the pop method, to remove the last two items that are "Severus", "Ron"
my_stack.pop()
my_stack.pop()
#then I'll append to the stack the item (a string) "Voldemort"
my_stack.append("Voldemort")

#if I print my_stack, the stack will contain in order "Draco", "Harry", "Hermione", "Voldemort"

print (my_stack)

my_stack = ["Draco", "Harry", "Hermione", "Voldemort"]