split list into nested lists by values in a loop (iterating values)

Question

I have a list of of lists like this:

nestedList = [[0],[0,1,2,3,4,6,7,8,9],[0,1,2,3,4,6,7,8,9],[1,2,3]]

and I have another homogeneous (same length) list of elements that I want to use to split the nestedList

lengthList = [[1],[5,4],[5,4],[3]]

I tried:

def split(arr, size):
     arrs = []
     while len(arr) > size:
         pice = arr[:size]
         arrs.append(pice)
         arr   = arr[size:]
     arrs.append(arr)
     return arrs

for i,j in zip(nestedList,lengthList):
    for k in j:
        myNewList.append(split(i,k))

but it doesn't work 100% right.

The output it gives is:

myNewList = [[[0]], [[0, 1, 2, 3, 4], [6, 7, 8, 9]], [[0, 1, 2, 3], [4, 6, 7, 8], [9]], [[0, 1, 2, 3, 4], [6, 7, 8, 9]], [[0, 1, 2, 3], [4, 6, 7, 8], [9]], [[1, 2, 3]]]

instead of

[[[0], [[0, 1, 2, 3, 4], [6, 7, 8, 9]], [[0, 1, 2, 3], [4, 6, 7, 8,9]], [[1, 2, 3]]]

Any help would be appreciated.

1. describe the problem (what you are trying to achieve) please 2. if you want code corrected / improved, there's CodeReview on stackexchange for that. — LetMeSOThat4U
– LetMeSOThat4U, Commented Feb 5, 2016 at 19:50
what do you mean by split the list with the homogenous list? — Jeremy Fisher
– Jeremy Fisher, Commented Feb 5, 2016 at 19:51

inspectorG4dget · Accepted Answer · 2016-02-05 19:54:39Z

2

nestedList = [[0],[0,1,2,3,4,6,7,8,9],[0,1,2,3,4,6,7,8,9],[1,2,3]]
lengthList = [[1],[5,4],[5,4],[3]]

answer = []
for lens,sub in zip(lengthList, nestedList):
    answer.append([])
    top = 0
    for l in lens:
        answer[-1].append(sub[top:top+l])
        top += l

Output:

In [2]: answer
Out[2]: 
[[[0]],
 [[0, 1, 2, 3, 4], [6, 7, 8, 9]],
 [[0, 1, 2, 3, 4], [6, 7, 8, 9]],
 [[1, 2, 3]]]

answered Feb 5, 2016 at 19:54

inspectorG4dget

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1 Comment

Mike Issa Over a year ago

Thank you @inspectorG4dget!

Mouhssen Bensalem · Accepted Answer · 2016-02-05 22:44:09Z

0

try this code

# stackoverflow.com
# Python
# split list into nested lists by values in a loop (iterating values)

nestedList = [[0],[0,1,2,3,4,6,7,8,9],[0,1,2,3,4,6,7,8,9],[1,2,3]]
lengthList = [[1],[5,4],[5,4],[3]]

def toOneList (array):
    oneList = []
    if len(array) > 0:
        for subList in array:
            for x in subList:
                oneList.append(x)
    return oneList

def grouping(array, size):
    newList = []
    i = 0
    for j in size:
        newList.append(array[i:i+j])
        i = i + j
    return newList


nestedList = toOneList(nestedList)
lengthList = toOneList(lengthList)

print(grouping(nestedList, lengthList))

answered Feb 5, 2016 at 22:44

Mouhssen Bensalem

1

Comments

andrewsi · Accepted Answer · 2016-02-05 22:46:02Z

0

Here is the solution you need

# stackoverflow.com
# Python
# split list into nested lists by values in a loop (iterating values)

nestedList = [[0],[0,1,2,3,4,6,7,8,9],[0,1,2,3,4,6,7,8,9],[1,2,3]]
lengthList = [[1],[5,4],[5,4],[3]]

def toOneList (array):
    oneList = []
    if len(array) > 0:
        for subList in array:
            for x in subList:
                oneList.append(x)
    return oneList

def grouping(array, size):
    newList = []
    i = 0
    for j in size:
        newList.append(array[i:i+j])
        i = i + j
    return newList


nestedList = toOneList(nestedList)
lengthList = toOneList(lengthList)

print(grouping(nestedList, lengthList))

edited Feb 5, 2016 at 22:46

andrewsi

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answered Feb 5, 2016 at 22:40

Mouhssen Bensalem

1

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