Q:

# Create a list by picking an odd-index items from the first list and even index items from the second using python programming

### Create a list by picking an odd-index items from the first list and even index items from the second

Given two lists, l1 and l2, write a program to create a third list l3 by picking an odd-index element from the list l1 and even index elements from the list l2.

Given:

``````l1 = [3, 6, 9, 12, 15, 18, 21]
l2 = [4, 8, 12, 16, 20, 24, 28]``````

Expected Output:

```Element at odd-index positions from list one
[6, 12, 18]
Element at even-index positions from list two
[4, 12, 20, 28]

Printing Final third list
[6, 12, 18, 4, 12, 20, 28]```

Hint:

Use list slicing

Solution:

To access a range of items in a list, use the slicing operator `:`. With this operator, you can specify where to start the slicing, end, and specify the step.

For example, the expression `list1[ start : stop : step]` returns the portion of the list from index start to index stop, at a step size step.

• for 1st list: Start from the 1st index with step value 2 so it will pick elements present at index 1, 3, 5, and so on
• for 2nd list: Start from the 0th index with step value 2 so it will pick elements present at index 0, 2, 4, and so on
``````list1 = [3, 6, 9, 12, 15, 18, 21]
list2 = [4, 8, 12, 16, 20, 24, 28]
res = list()

odd_elements = list1[1::2]
print("Element at odd-index positions from list one")
print(odd_elements)

even_elements = list2[0::2]
print("Element at even-index positions from list two")
print(even_elements)

print("Printing Final third list")
res.extend(odd_elements)
res.extend(even_elements)
print(res)
``````