Insert two or more values at same index of list

Question

Not asking particularly about the slicing, Basically I want to replace the value of specific index of list by 2 or more elements.

For Example:

list_a = [1, 2, 3] and list_b = [4, 5] so what I want is result = [4, 5, 2, 3]

Asked By: harry jame

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Source

Answer 1

You can achieve this using below,
First you need to pop 0 index value, then try to reverse the b and loop over to insert values of b in 0 index of a

a = [1, 2, 3]
b = [4, 5]
a.pop(0)

for i in b.reverse():
    a.insert(0, i)
print(a)

Output:

[4, 5, 2, 3]

Answered By: Usman Arshad

Answer 2

If you want a new list:

idx = 0
result = list_a[:idx]+list_b+list_a[idx+1:]

Output: [4, 5, 2, 3]

If you want to modify the list in place:

idx = 0
list_a[:] = list_a[:idx]+list_b+list_a[idx+1:]

# OR (see @Nineteendo's comment)
list_a[idx:idx + 1] = list_b

step by step

# get values up to the insertion point
list_a[:idx]
# []

# get values after the insertion point
list_a[idx+1:]
# [2, 3]

# combine everything in a single list
list_a[:idx]+list_b+list_a[idx+1:]
# [4, 5, 2, 3]

Answered By: mozway

Insert two or more values at same index of list

Question:

Answers:

step by step