从列表中的最后一个元素中删除逗号

Question

I am trying to return the array of number without the last comma. ex)

[['0,0,0,0,0'], ['1,1,1,1'], ['2,2,2'], ['3,3'], ['4']]

I keep returning this

[['0,0,0,0,0,'], ['1,1,1,1,'], ['2,2,2,'], ['3,3,'], ['4,']]

The definiton is as follow:

def array(i):
    arraylist = []
    for num in range(0, i):
        arraylist.append([])
        if num is 0:
            print (str(0) + " ") * i
            arraylist[num].append((str(0)) * (i-(num)))
        else:
            print (str(num) + " ") * (i - (num))
            arraylist[num].append((str(num)+",") * (i-(num)))
    return arraylist

Aditionally if you could help me take out the quotations in the returned array.

Answer 1

If by remove the trailing comma and the quotations you mean that you wanna return a list of lists of numbers, this is what your function needs to do:

def array(i):
    arraylist = []
    for num in range(0, i):
        arraylist.append((i - num) * [num])
    return arraylist

from my shell:

>>> print array(5)
[[0, 0, 0, 0, 0], [1, 1, 1, 1], [2, 2, 2], [3, 3], [4]]

if what you want is what you had before but without the trailing coma, ie a list of lists with one one array inside the inner lists, just remove the last char from each string after building it:

def array(i):
    arraylist = []
    for num in range(0, i):
        arraylist.append([])
        if num is 0:
            arraylist[num].append((str(0) + ',') * (i-(num)))
        else:
            arraylist[num].append((str(num)+",") * (i-(num)))
        arraylist[num][0] = arraylist[num][0][:-1]
    return arraylist

from my shell:

>>> print array(5)
[['0, 0, 0, 0, 0'], ['1, 1, 1, 1'], ['2, 2, 2'], ['3, 3'], ['4']]

Answer 2

This works:

>>> def array(i):
...     l = []
...     for num in xrange(i):
...         l.append([num] * (i - num))
...     return l

Then:

>>> array(5)
[[0, 0, 0, 0, 0], [1, 1, 1, 1], [2, 2, 2], [3, 3], [4]]