Python: Interleave multiple lists of different lengths using itertools module

Last update on April 22 2025 12:54:55 (UTC/GMT +8 hours)

38. Interleave Different Length Lists

Write a Python program to interleave a number of lists of different lengths using the itertools module.

Sample Solution:

Python Code:

from itertools import chain, zip_longest
def interleave_diff_len_lists(list1, list2, list3, list4):
    return [x for x in chain(*zip_longest(list1, list2, list3, list4)) if x is not None]    
    
nums1 = [2, 4, 7, 0, 5, 8]
nums2 = [2, 5, 8]
nums3 = [0, 1]
nums4 = [3, 3, -1, 7]

print("\nOriginal lists:")
print(nums1)
print(nums2)
print(nums3)
print(nums4)

print("\nInterleave said lists of different lengths:")
print(interleave_diff_len_lists(nums1, nums2, nums3, nums4))

Sample Output:

Original lists:
[2, 4, 7, 0, 5, 8]
[2, 5, 8]
[0, 1]
[3, 3, -1, 7]

Interleave said lists of different lengths:
[2, 2, 0, 3, 4, 5, 1, 3, 7, 8, -1, 0, 7, 5, 8]

For more Practice: Solve these Related Problems:

• Write a Python program to interleave multiple lists of different lengths using itertools.zip_longest and then remove any None values.
• Write a Python program to merge several lists of varying lengths by interleaving their elements and then flatten the result.
• Write a Python program to create an iterator that alternates elements from multiple lists of different sizes and then map a function to convert them into strings.
• Write a Python program to interleave a number of lists with unequal lengths using itertools and then sort the combined list in ascending order.

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