0
Good afternoon, I created a program that needs to sort the numbers and write them in string form, the problem occurs after I order, it seems to be returning an empty list, because when I try to run toString, when I debuggo I realize that it always takes an empty list...
My thought was, I’ll go through the existing numbers, find the smallest, play on a new list and delete the smallest number from the previous list and return to the new list.
I accept any tips because I’m a beginner.
class Ordenacao():
def __init__(self, array_para_ordenar:[]):
self.__lista = array_para_ordenar
def ordena(self):
array = self.__lista
lista1 = []
for j in range(len(array)):
pos = 0
for i in range(1, len(array)):
if array[pos] > array[i]:
pos = i
lista1.append(array[pos])
array.remove(array[pos])
return lista1
def toString(self):
array = self.__lista
for i in range(len(array)):
array[i] = str(array[i])
str1 = ','.join(array)
return (str1)
teste = [9, 0, 1]
orde = Ordenacao(teste)
orde.ordena()
orde.toString()
I think the problem is your job
ordenait seems that it returns an ordered array, it removes the items from the arrayself.__listain the process. I think in the end it should replace theself.__listawith the new ordered array.– Icaro Martins
@Victoraraújo Little locust, I don’t know Python, but you can see that 1) if the ordering and return of the ordered list is correct, then when calling
orde.ordena()You’re not doing anything with what this call returns, you’re not keeping it on another list or anything. 2) You may not need to return anything, you could just point to__listathat keeps in the object to the one that you ordered, within the concept of updating fields of objects (that personally do not find good beginner mess at the beginning of the programming study, because POO is something kind of advanced, but anyway, is fashionable).– Piovezan
Where in the code
array = self.__listareplace witharray = self.__lista[:]and at the end of the code do where you areorde.ordena()doprint(orde.ordena())– Augusto Vasques
Although the titles of the questions suggested above are different, the basic problem is the same: you are modifying the original list, as already explained in the comments (which also gave the solution)
– hkotsubo
Solution no, only a repair the solution goes beyond the scope of the question.
– Augusto Vasques
Well, from what the AP said, the problem is that he’s trying to print out a list that he emptied himself, according to the logic he gave in the question he used to sort. All that was missing was to play the ordered list over the emptied list as well (in case you do not need to copy the items one by one, just point to the variable
__listafor the list that was ordered), there thetoString()you’ll have a better chance of working.– Piovezan
When you do
array2 = array1, everything you do onarray2will happen in thearray1also. You have to clone if you want to create an independent copy:array2 = array1.copy()– Natan Fernandes
Taking advantage, in Python there is the special method
__str__that you can use instead oftoString. And I understand that you may want to sort manually (maybe to train), but in real systems, prefer to use what you already have ready: https://ideone.com/GsRZ9L– hkotsubo
@Natanfernandes A
lista1where are going the items ordered by what I understand does not point to the original, is another list, so what I said should work, just do__lista = lista1at the end of the ordination.– Piovezan
@hkotsubo, the one you presented is the solution.
– Augusto Vasques
@Augustovasques I reread the question several times and my understanding is that the main/specific problem is the fact that the list is empty at the end (and the reason is addressed in the dups indicated). Everything else (
__str__, the sorting algorithm itself, etc.), I understand it is secondary, so I keep closing (by the way, if anyone has other dup suggestions, you can comment that I add). But of course, if someone disagrees with the closure, just use the usual means (vote to reopen, open discussion on [goal], etc)– hkotsubo
Well, I believe I understood where I went wrong, it would be because I should not delete the elements of the array that is conditioned in my constructor method, right? What I did to solve was kind of a gambit in oderna() and put self. __list = list1 before returning. Thank you all for the tips
– Victor Araújo
and @Augustovasques, could you explain to me, please explain why you need to use the [:] in the = self array. __list[:]
– Victor Araújo
@hkotsubo, I do not disagree and do not want to reopen the question because the question is implicitly broad, because initially it presents the problem mentioned but brings with it several errors of concept that should be resolved and carefully in a solution. That’s why I don’t consider my code as a solution but as a repair to what the author is already doing while their code yes eliminates those problems that bother me.
– Augusto Vasques
@Victoraraújo this code makes a superficial clone of
self.__lista.– Augusto Vasques
@Augustovasques show!! did not know this, the part of Class already came ready, but did not understand why had these [:] Thank you very much!
– Victor Araújo
@VictorAraújo https://stackoverflow.com/q/6167238
– hkotsubo