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").

[delete4ever]

harry_potter_stack = deque ()
harry_potter_stack.append("Draco")
harry_potter_stack.append("Harry")
harry_potter_stack.append("Hermione")
harry_potter_stack.append("Ron")
harry_potter_stack.append("Severus")
harry_potter_stack.pop()
# "Severus" was returned and then removed from the top of the stack, now the stack is ["Draco", "Harry", "Hermione", "Ron"]
harry_potter_stack.pop()
# "Ron" was returned and then removed from the top of the stack, now the stack is ["Draco", "Harry", "Hermione"]
harry_potter_stack.append("Voldemort")
# "Voldemort" was added to the top of the stack, now the stack is ["Draco", "Harry", "Hermione", "Voldemort"]

[mjavadf]

by calling my_stack.pop() the top item of stack will be returned and then will be removed
stack status after calling this method 2 times: deque(['Draco', 'Harry', 'Hermione'])
by calling harry_potter_stack.append("Voldemort") the '"Voldemort" will be added to top of the stack
stack status after calling this method: deque(['Draco', 'Harry', 'Hermione', 'Voldemort'])

[n1kg0r]

from collections import deque

my_stack = deque(["Draco", "Harry", "Hermione", "Ron", "Severus"])
my_stack.pop() # deque(['Draco', 'Harry', 'Hermione', 'Ron']) <- "Severus" taken from the 'top' of the stack
my_stack.pop() # deque(['Draco', 'Harry', 'Hermione']) <- "Ron" taken from the 'top' of the stack
my_stack.append("Voldemort") # deque(['Draco', 'Harry', 'Hermione']) <- "Voldemort" put on the 'top' of the stack

[GaiaOrtona]

from collections import deque

Friends_stack = deque()
Friends_stack.append("Draco")
Friends_stack.append("Harry")
Friends_stack.append("Hermione")
Friends_stack.append("Ron")
Friends_stack.append("Severus")
Friends_stack.pop()
#based on the LIFO strategy, "Severus" has been removed from the stack
print(Friends_stack)
Friends_stack.pop()
#based on the LIFO strategy, "Ron" has been removed from the stack
print(Friends_stack)
Friends_stack.append("Voldemort")
#"Voldemort" has been added to the stack
print(Friends_stack)

[SalvatoreDiMarzo]

from _collections import deque

def test_my_stack(my_list, expected):
    if my_list == expected:
        return True
    else:
        return False

my_stack = deque(["Draco", "Harry", "Hermione", "Ron", "Severus"])
my_stack.pop()      # Severus is removed#
my_stack.pop()      # Ron is removed#
my_stack.append("Voldemort")       # Voldemort is added#
print(my_stack)
print(test_my_stack(my_stack, deque(["Draco", "Harry", "Hermione", "Voldemort"])))

[AmirAliyan74]

[giorgiacrosilla]

from collections import deque

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

[lucia1299]

from collections import deque

my_stack = deque ()
my_stack.append("Harry")
my_stack.append("Hermione")
my_stack.append("Ron")
my_stack.append("Draco")
my_stack.append("Severus")

print(my_stack)

my_stack.pop()
print(my_stack)

my_stack.pop()
print(my_stack)

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

OUTPUT(s):

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

[corrado877]

[EricaAndreose]

[mary-lev]

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

[ranacoskun]

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

[tiglio95]

my_stack = deque()
my_stack.append("Draco")
my_stack.append("Harry")
my_stack.append("Hermione")
my_stack.append("Ron")
my_stack.append("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', 'Voldemort'])

[lvcasmariani]

[ChiaraParravicini]

from collections import deque

my_stack = deque(["Draco", "Harry",
"Hermione", "Ron", "Severus"])
my_stack.pop()
# "Severus", the item on top of the stack, has been removed 
my_stack.pop()
# "Ron", now being the item on top of the stack, has been removed
my_stack.append("Voldemort")
# "Voldermort" has been added on top of the stack
print(my_stack)
# now my_stack contains: deque(["Draco", "Harry", "Hermione", "Voldemort"])

[alka2696]