How to create the fixed length of empty list or array and append the required item from the starting index of list or array in python

Question

My requirement is l1 should be fixed length & l2 length will be vary dynamically.

l1 = [None] * 24
l2 = [1,2,3,4,5,6,7,8,9,10] 
(or)
l2 = [1,2,3,4,5] 
(or)
l2 = list(range(40))

Now I need to append or insert the second list or array from the starting position. My final output expected as below ( Means after append or insert the L1 length always 24)

Case 1:

    l1 = [1,2,3,4,5,6,7,8,9,10, None, None, None, None, None, None, None, None, None, None, None, None, None, None]

Case 2:

    l1 = [1,2,3,4,5,None, None,None, None,None None, None, None, None, None, None, None, None, None, None, None, None, None, None]

Case 3:
(Ignore after 24th index)
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23]

Is there any optimal solution using python list or numpy array or any other lib?

https://stackoverflow.com/questions/10617045/how-to-create-a-fix-size-list-in-python please have a look this link for getting idea about the performance — RafsanJany, Mar 03 '21 at 04:26

score 0 · Accepted Answer · answered Mar 03 '21 at 07:52

0

You can use subscripting to assign l2 (or a part of it) to a subset of l1 (i.e. using the smallest length):

l1[:len(l2)] = l2[:min(len(l1),len(l2))]

answered Mar 03 '21 at 07:52

Alain T.

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How to create the fixed length of empty list or array and append the required item from the starting index of list or array in python

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