How Can I Pythonically Interleave Two Lists of Unequal Lengths?

Pythonic Interleaving of Lists

Combining two lists in an alternating fashion is a common task in programming. When the first list has exactly one more item than the second, there are several approaches to achieve this in Python. Here are a few Pythonic options:

1. Using Slicing:

One method is to use slicing to create a new list that interleaves the elements from both lists. This can be done with the following steps:

1. Create a new list with a length equal to the sum of the lengths of the two input lists.
2. Assign the even-indexed elements of the new list to the items from the first input list.
3. Assign the odd-indexed elements of the new list to the items from the second input list.

Here's an example:

list1 = ['f', 'o', 'o']
list2 = ['hello', 'world']
result = [None]*(len(list1)+len(list2))
result[::2] = list1
result[1::2] = list2
print(result)

Output:

['f', 'hello', 'o', 'world', 'o']

2. Using the itertools Package:

Python's itertools package provides a convenient function called islice that can be used to iterate over elements of a list in a specified interval. Here's how you can use it to interleave two lists:

import itertools
list1 = ['f', 'o', 'o']
list2 = ['hello', 'world']
result = list(itertools.chain(*itertools.zip_longest(list1, list2)))
print(result)

Output:

['f', 'hello', 'o', 'world', 'o']

The above is the detailed content of How Can I Pythonically Interleave Two Lists of Unequal Lengths?. For more information, please follow other related articles on the PHP Chinese website!