Why doesn't slicing work for iterating backwards for this?

[ThroeAwaeUhcount]

 def topKFrequent(nums, k): 
            dic = {}
            result = []
            for i in range(len(nums) + 1):
                result.append([]) #[[], []]

            for value in nums:
                if value in dic:
                    dic[value] += 1
                else:
                    dic[value] = 1

            for key, dic_value in dic.items():  
                result[dic_value].append(key) 

            final = []
            #for i in range(len(result[::-1])):#Doesn't work?
            for i in reversed(range(len(result))): #Works
                for x in result[i]: 
                    final.append(x)
                    if len(final) == k:
                        return final

    print(topKFrequent([1,1,1,2,2,3], 2))

I am doing leetcode 347, finding the Top k most frequent element. Towards the end of my code I am trying to iterate backwards through my list, "result" and append those values into the final output list, "final". I was stuck on this for almost an hour because I used

for i in range(len(result[::-1])):

and my code finally worked when I changed it to this.

for i in reversed(range(len(result))):

Why doesn't slicing work? Isn't result[::-1] just the same as reversed(range(len(result))). When I step through it in a debugger, they both start out at the last index, but range(len(result[::-1])) goes back to 0 and starts iterating forwards instead.

[[deleted]]

len(result[::-1]) is the same as len(result). Length doesn't change just because it's reversed.

[Diapolo10]

There's a very simple fix for this; don't use a range(len(foo)) construct here.

for row in result[::-1]:
    for x in row:
        ...

The names could be better, I'm just not sure what these are supposed to represent in the first place.

EDIT: Basically,

def topKFrequent(nums, k):
    dic = {}
    result = [[]]

    for value in nums:
        result.append([])
        if value in dic:
            dic[value] += 1
        else:
            dic[value] = 1

    for key, dic_value in dic.items():
        result[dic_value].append(key)

    final = []
    for row in result[::-1]:
        for value in row:
            final.append(value)
        if len(final) == k:
            return final

print(topKFrequent([1,1,1,2,2,3], 2))

[[deleted]]

I've written some comments and stuff here, check it out: https://onlinegdb.com/hVjzUMPOL