尝试在python中排序2d数组以输出高分列表

Question

So I am making a game server thing that lets users login and choose a game to play and then adds whatever score they got to a notepad file in the format: (ie blackjack) username, #chips, "chips". Now i want to sort through all the scores in the file to show on my gui but I'm not allowed to use built in functions like sorted but rather have to come up with an algorithm. I've tried a bubble sort and insertion sort without any luck. Here's what I have so far:

blackjackList = [['harsh', '4', 'chips'], ['ahmed', '25', 'chips'], ['yousef', '1003', 'chips'], ['krushangi', '200', 'chips'], ['bombberman', '1202', 'chips']]
def bubbleSort(alist):
    for passnum in range(len(alist)-1,0,-1):
        for i in range(passnum):
            if alist[i][1]>alist[i+1][1]:
                temp = alist[i]
                alist[i] = alist[i+1]
                alist[i+1] = temp
        return alist

This currently outputs

[['ahmed', '25', 'chips'], ['yousef', '1003', 'chips'], ['krushangi', '200', 'chips'], ['bombberman', '1202', 'chips'], ['harsh', '4', 'chips']]

when I use it with blackjacklist but i want it to make blackjacklist go in order from ascending to descending scores.

Answer 1

Your problem is that the return statement is indented too much and sits inside the for loop therefore it only does one pass through before returning.

Also, you are comparing the numbers as strings. This will not give the expected order (eg "10" is less than "2"). You should use int() to convert them to integers which will then sort correctly.

Answer 2

You can use quicksort to sort the arrays.

>>> blackjackList = [['harsh', '4', 'chips'], ['ahmed', '25', 'chips'], ['yousef', '1003', 'chips'], ['krushangi', '200', 'chips'], ['bombberman', '1202', 'chips']]
>>> def quicksort(arr):
...     if len(arr)==0: return []
...     if len(arr)==1: return arr
...     left = [i for i in arr[1:] if int(i[1])<int(arr[0][1])]    # for descending, exchange
...     right = [i for i in arr[1:] if int(i[1])>=int(arr[0][1])]  # these two values
...     return quicksort(left)+[arr[0]]+quicksort(right)
...
>>> quicksort(blackjackList)
[['harsh', '4', 'chips'], ['ahmed', '25', 'chips'], ['krushangi', '200', 'chips'], ['yousef', '1003', 'chips'], ['bombberman', '1202', 'chips']]

The above code gives the ascending sorted list. To get descending sorted list, just exchange the values for left and right in the code.