Two methods for fast pairing lists in Python
In Python, there are two commonly used methods for quickly pairing lists.
zip
Before 3.10, the zip function combined with slicing in Python was used to pair elements. The zip() function takes two or more lists as input and returns a new list of tuples, where each tuple contains elements from the corresponding positions of the input lists. This method is useful when you want to iterate over multiple lists simultaneously.
list1 = [1, 2, 3]
list2 = ['A', 'B', 'C']
pairs = list(zip(list1, list2))
The resulting pairs list will be [(1, 'A'), (2, 'B'), (3, 'C')].
pairwise
In 3.10, you can now use pairwise() from itertools:
from itertools import pairwise
numbers = range(1, 6)
pairs = list(pairwise(numbers))
print(pairs) # [(1, 2), (2, 3), (3, 4), (4, 5)]
The itertools.pairwise() method is more versatile and can be applied to any iterable object. It is slightly more complex than the zip() method but provides greater flexibility for different iterable types.
It is particularly useful for sliding window problems, such as sliding window problems in data analysis or sequence processing.