如何根据原始列表中与设置值不同的元素对列表进行切片（或创建子列表）

Question

This is my first time asking a question here, so please don't roast me too much as I try to get the swing of things.

I am working on some code using Python 3. So, in my code I generate a list. For the sake of specificity, suppose I am working with the following list:

a = [3344, 3354, 3364, 3364, 3374, 3374, 3384, 3384, 3394, 3394, 3404, 3404, 3414, 3414, 3424, 3434]

I would like to sort this list into the following sublists:

sub1 = [3344, 3354, 3364, 3374]
sub2 = [3364, 3374, 3384, 3394]
sub3 = [3384, 3394, 3404, 3414]
sub4 = [3404, 3414, 3424, 3434]

So, I would like to sort the original list into sublists based on the elements that differ by a known value, in this case 10.

I am unable to use index-based slicing and have not yet been able to implement any kind of lambda function to accomplish this. I have searched through the depths of Stack Overflow and have not found anything particularly helpful.

Thank you for the help.

Update:

I wanted to add some more information to clear up any confusion resulting from lack of specificity in my language. The goal is to generate sublists with four elements from the original list, with the elements of the sublist differing by a value of 10.

To better explain what I am trying to accomplish here, I will provide a second list and the desired output sublists.

b = [3384, 3404, 3344, 3394, 3374, 3414, 3354, 3404, 3384, 3424, 3364, 3414, 3394, 3364, 3434, 3374]

The desired output would look something like this:

sublist1 = [3344, 3354, 3364, 3374]
sublist2 = [3364, 3374, 3384, 3394]
sublist3 = [3384, 3394, 3404, 3414]
sublist4 = [3404, 3414, 3424, 3434]

I need to be able to generate this output, as these sublists will be used as input values for different functions later on... Capturing the degenerate values is a must.

I hope this clears things up!

Answer 1

You can use a nested for loop that appends an item in a to an existing sublist whose length is less than 4 and whose last item is 10 less than the item, or otherwise create a new sublist with the item:

l = []
for i in a:
    for s in l:
        if len(l) < 4 and s[-1] + 10 == i:
            s.append(i)
            break
    else:
        l.append([i])

Given your sample input, l would become:

[
    [3344, 3354, 3364, 3374],
    [3364, 3374, 3384, 3394],
    [3384, 3394, 3404, 3414],
    [3404, 3414, 3424, 3434]
]

Note that your expected output is incorrect because the items in your input a can be sorted into two sublists without breaking the rule of all adjacent items differing by 10.

Answer 2

Use sorted with set and a loop

b = [3384, 3404, 3344, 3394, 3374, 3414, 3354, 3404, 3384, 3424, 3364, 3414, 3394, 3364, 3434, 3374]

lst = sorted(set(b))
for i in range(4):
    print(lst[i*2:i*2+4])

 [3344, 3354, 3364, 3374] [3364, 3374, 3384, 3394] [3384, 3394, 3404, 3414] [3404, 3414, 3424, 3434]