经过for循环后计数器变量未更改

Question

我是Python的初学者，我正在研究一个问题，我希望计数器变量每次经过for循环时都减少一。它显示在这里。

overall_triangle = """75
95 64
17 47 82
18 35 87 10
20 04 82 47 65
19 01 23 75 03 34
88 02 77 73 07 63 67
99 65 04 28 06 16 70 92
41 41 26 56 83 40 80 70 33
41 48 72 33 47 32 37 16 94 29
53 71 44 65 25 43 91 52 97 51 14
70 11 33 28 77 73 17 78 39 68 17 57
91 71 52 38 17 14 91 43 58 50 27 29 48
63 66 04 68 89 53 67 30 73 16 69 87 40 31
04 62 98 27 23 09 70 98 73 93 38 53 60 04 23"""

overall_triangle_2d = [i.split() for i in overall_triangle.split('
')]

for i in range(0, len(overall_triangle_2d)):
    for j in range(0, len(overall_triangle_2d[i])):
        overall_triangle_2d[i][j] = int(overall_triangle_2d[i][j])

counter = 13
greatest_sum = []

for i in range(0, len(overall_triangle_2d[counter])):
    print(counter)
    num_1 = int(overall_triangle_2d[counter][i]) + int(overall_triangle_2d[counter + 1][i])
    # print(num_1)
    num_2 = int(overall_triangle_2d[counter][i]) + int(overall_triangle_2d[counter + 1][i + 1])
    # print(num_2)
    empty = []
    if num_1 > num_2:
        greatest_sum.append(num_1)
    elif num_1 == num_2:
        greatest_sum.append(num_1)
    else:
        greatest_sum.append(num_2)
    # print(greatest_sum)
    if len(greatest_sum) == counter + 1:
        # print(overall_triangle_2d[counter + 1])
        overall_triangle_2d[counter + 1] = empty
        # print(overall_triangle_2d[counter + 1])
        # print(overall_triangle_2d[counter])
        overall_triangle_2d[counter] = greatest_sum
        # print(overall_triangle_2d[counter])
        # print(counter)
        if counter == 0:
            print(greatest_sum)
            break
        else:
            greatest_sum = []
            counter = counter - 1
            # print(counter)
    else:
        continue

每次通过计数器变量运行它都不会更改。请让我知道我可以做些什么。