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").

[SarahTew]

1. my_stack = deque(["Draco", "Harry", "Hermione", "Ron"])
2. my_stack = deque(["Draco", "Harry", "Hermione"])
3. my_stack = deque(["Draco", "Harry", "Hermione", "Voldemort"])

[ChiaraCati]

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

[margheparla]

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)

[yunglong28]

from _collections import deque # This imports deque my_stack = deque() # This creates a new stack

my_stack.append("Draco") # Now we add the elements my_stack.append("Harry") my_stack.append("Hermione") my_stack.append("Ron") my_stack.append("Severus") deque(['Draco', 'Harry', 'Hermione', 'Ron', 'Severus'])

my_stack.pop() # Now we execute the exercise my_stack.pop() my_stack.append("Voldemort") print(my_stack) deque(['Draco', 'Harry', 'Hermione', 'Voldemort'])

[AleRosae]

from _collections import deque
my_stack = deque(["Draco", "Harry", "Hermione", "Ron", "Severus"])
my_stack.pop() # returns deque(['Draco', 'Harry', 'Hermione', 'Ron'])
my_stack.pop() # returns deque(['Draco', 'Harry', 'Hermione'])
my_stack.append("Voldemort") # returns deque(['Draco', 'Harry', 'Hermione', 'Voldermort'])

[dbrembilla]

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

[edoardodalborgo]

from collections import deque
my_stack = deque(["Draco", "Harry", "Hermione", "Ron", "Severus"])
my_stack.pop() #it removes the last string of the stack ("Severus") and return "Severus"
my_stack.pop() #it removes the last string of the stack ("Ron") and return "Ron"
my_stack.append("Voldemort") #it adds the string "Voldemort" at the end of the stack
print(my_stack) #it prints deque["Draco", "Harry", "Hermione", "Voldemort"]

[laurentfintoni]

status 1 - deque(["Ron", "Hermione", "Harry", "Draco"]) status 2 - deque(["Hermione", "Harry", "Draco"]) status 3 - deque(["Voldemort", "Hermione", "Harry", "Draco"])

[vanessabonanno]

my_stack = deque(["Draco", "Harry", "Hermione", "Ron", "Severus"]) my_stack.pop() #current status: deque(["Draco", "Harry", "Hermione", "Ron"]) my_stack.pop() #current status: deque(["Draco", "Harry", "Hermione"]) my_stack.append("Voldemort") #current status: deque(["Draco", "Harry", "Hermione", "Voldermort"])

[AlessandraFa]

from collections import deque
my_stack = deque(["Draco", "Harry", "Hermione", "Ron", "Severus"])
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']) # the last item of the deque ("Severus") is returned and removed
deque(['Draco', 'Harry', 'Hermione']) # after deleting "Severus", the last item of the deque is "Ron", which is again returned and removed from my_stack
deque(['Draco', 'Harry', 'Hermione', 'Voldemort']) # The string "Voldemort" is added at the end of the deque

[LuisAmmi]

my_stack = deque(["Draco","Harry","Hermione","Ron","Severus"]):
my_stack.pop() #the last item is removed and the algorithm returns deque(["Draco","Harry","Hermione","Ron"])
my_stack.pop() #returns deque(["Draco","Harry","Hermione"])
my_stack.append("Voldemort") #addition of this item
print(my_stack) #it will print ["Draco","Harry","Hermione","Voldemort"]

[gabrielefiorenza]

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)

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

[penelopelask]

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'])

[giorgiasampo]

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

1 - my_stack.pop(): my_stack = deque(["Draco", "Harry", "Hermione", "Ron"]) 2 - my_stack.pop(): my_stack = deque(["Draco", "Harry", "Hermione"]) 3 - my_stack.append("Voldemort"): my_stack = deque(["Draco", "Harry", "Hermione", "Voldemort"])

[fcagnola]

The stack will first eliminate the last element, then the second-to last, and then add the new one. Each step will modify the stack as follows: ["Draco", "Harry", "Hermione", "Ron"] then ["Draco", "Harry", "Hermione"] and finally ["Draco", "Harry", "Hermione", "Voldemort"]

[samuelespotti]

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'])

[GiuliaMenna]

from collections import deque

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

print(deque)

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

[SusannaPinotti]

from collections import deque

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

my_stack.pop()
print(my_stack)

my_stack.pop()
print(my_stack)

my_stack.append("voldemort")
print(my_stack)

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

[alicebordignon]

from collections import deque my_stack = deque(["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'])

[DeniseBas]

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'])

[IlaRoss]

my_stack: after my_stack.pop() --> my_stack = deque (["Draco", "Harry", "Hermione", "Ron"]) after my_stack.pop() --> my_stack = deque (["Draco", "Harry", "Hermione"]) after my_stack.append("Voldemort") --> my_stack = deque (["Draco", "Harry", "Hermione", "Voldemort"])