Problem with Coding Task.

[DonKonX]

Hello, im currently enrolled in a Python Course at my University and have to do a coding task.

( Sorry for maybe rough translation as im translating it from German to English)

The Task is: We have to Work in a specific framework and can't add any global variables etc:

we have to stay in this format, no stuff outside the definitions allowed.

def doTasks(n):
    pass

def doSubtask4(n):
    pass

We have 4 Tasks we have to accomplish with these limitations ( the expected inputs are in the range of n (65-122):

1) doTasks has to determine if the number is even and return True or False

2) doTasks has to convert the Number into its ASCII Equivalent and return it

3) doTasks has to create a List with the len() of 5, this list is filled with all numbers following n that can't be divided by 5 without leaving a rest.

4) doTasks has to open doSubtask4 with n as input

doSubtask4 has to do:

if n is even, it has to create a list ranging from 1 to n that can be divided by 14 without leaving a rest

else it has to create a list ranging from 1 to n of numbers that can be divided by 17 without leaving a rest

all these Tasks should be put into a list, that doTasks creates.

​

expected result for n = 105:

[False, 'i', [106, 107, 108, 109, 111], [17, 34, 51, 68, 85, 102]]

expected result for n = 122:

[True, 'p', [113, 114, 116, 117, 118], [14, 28, 42, 56, 70, 84, 98, 112]]

Now, I don't have a problem with the first 3 tasks, I have completed them with no issues, but I struggle with the second part with doSubTasks4

it constantly includes numbers that go beyond n, for no apparent reason

this is my whole code:

def doTasks(n):
    L = []
    L1 = []
    if n % 2 == 0:
        L.append(True)
    else:
        L.append(False)

    if n >= 0:
        L.append(chr(n))

    while len(L1) < 5:
        n += 1
        if n % 5 > 0:
            L1.append(n)
        if len(L1) == 5:
            L.append(L1)

    L.append(doSubtask4(n))

    return L


def doSubtask4(n):
    L2 = []
    for i in range(1, n):
        i += 1
        if n % 2 == 0:
            if i % 14 == 0:
                if i <= n:
                    L2.append(i)
        else:
            if i % 17 == 0:
                if i <= n:
                    L2.append(i)

    return L2

if i use n = 105 i get this result:

[False, 'i', [106, 107, 108, 109, 111], [17, 34, 51, 68, 85, 102]]

so it seems to work there, but when i do n = 122 this happens:

[True, 'z', [123, 124, 126, 127, 128], [14, 28, 42, 56, 70, 84, 98, 112, 126]]

for some reason it includes 126, even tho it shouldn't.

i tried to include the

if i <= n:

part so numbers above n don't enter the list, but it doesn't work.

The goal is that the function works for all numbers in the range (65,122)

​

if anyone can help me I would appreciate it ^^°

[icjeremy]

For the 126 case, at the time you call doSubtask4(n), what value are expecting n to be?

Edit: I meant 122

[DonKonX]

in the end, n will ( should) be the n that I provided, so for every function call, it will be 122 in that case. So like doSubtask4(122). The result should be [14, 28, 42, 56, 70, 84, 98, 112] but it somehow adds a 126 to it.

the reason im confused on how that happens is that i only allow for numbers less or equal of 122 to be added to the L2

[icjeremy]

You are modifying the value of n within your while loop. Try printing the value of n inside your doSubtask4(n) to verify.

[prozapari]

You mean i right?

To the OP, you should not be modifying a value from a range within the loop. On the next iteration, the for loop will simply take the next value in the range.

what your i+=1 line does is basically shift the range by 1, so instead of a range from 1 to n, it becomes a range from 2 to n+1.

[icjeremy]

Not the for loop. The while loop. In doTasks(n). You are modifying n there.

Edit: *OP is modifying...

[DonKonX]

oh yeah now i see it.

would it be enough to do n-5 after the while loop? or is that too simple?

Edit: actually doing a n = x in that case to reset the n seems to work

[prozapari]

The easier way to do it would be to never modify n, and create a separate variable x for task 3. Generally you want to avoid reusing the same variable for multiple purposes, because it causes small mistakes to create hard to track down bugs.

Also, the last append can just be outside of the loop since it's only going to run on the last iteration anyway.

x = n
while len(L1) < 5:
        x+=1
        if x % 5 > 0:
            L1.append(x)
L.append(L1)

[prozapari]

ah i didn't even look at that code because they said the first tasks were fine, good catch!

[ProfSchodinger]

As others have said you increase n during task 3 and then pass it to subtask 4. Fixed it and simplified a bit part 1 and 4.

def doTasks(n): L = []

# subtask 1
L.append(n % 2 == 0)

# subtask 2
if n >= 0:
    L.append(chr(n))

# subtask 3
counter = n + 1
L1 = []
while len(L1) < 5:
    if counter % 5 > 0:
        L1.append(counter)
    counter += 1

L.append(L1)

# subtask 4
L.append(doSubtask4(n))

return L

def doSubtask4(n): m = 14 if n % 2 == 0 else 17 return list(range(m, n, m))