[Solved] Get Pairs of List Python [duplicate]

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Introduction

This question is a duplicate of a previously asked question. This post provides an introduction to the Python programming language and how to use it to get pairs of a list. Python is a powerful and versatile programming language that can be used to solve a variety of problems. It is easy to learn and can be used to quickly and efficiently solve problems. In this post, we will discuss how to use Python to get pairs of a list. We will look at different methods of doing this, including using the built-in functions and writing custom code. We will also discuss the advantages and disadvantages of each approach.

Solution

This question already has an answer here:

Finding all pairs in a list of numbers [duplicate]

Answer:

def get_pairs(lst):
pairs = []
for i in range(len(lst)):
for j in range(i+1, len(lst)):
pairs.append((lst[i], lst[j]))
return pairs

# example
lst = [1, 2, 3, 4]
print(get_pairs(lst))
# [(1, 2), (1, 3), (1, 4), (2, 3), (2, 4), (3, 4)]


Sure, there are many ways. Simplest:

def func(alist):
    return zip(alist, alist[1:])

This spends a lot of memory in Python 2, since zip makes an actual list and so does the slicing. There are several alternatives focused on generators that offer memory savings, such as a very simple:

def func(alist):
    it = iter(alist)
    old = next(it, None)
    for new in it:
        yield old, new
        old = new

Or you can get fancier deploying the powerful itertools instead, as in the pairwise recipe proposed by @HughBothwell .

1

solved Get Pairs of List Python [duplicate]


This question already has an answer here:
Iterating over every two elements in a list 8 answers

If you have a list of items and you want to get all the possible pairs of items from the list, you can use the itertools.combinations() function in Python. This function takes two arguments: an iterable object (in this case, a list) and an integer that specifies the size of the combinations that you want to generate. For example, if you have a list of numbers and you want to get all the possible pairs of numbers, you can use the following code:

import itertools

my_list = [1, 2, 3, 4]

pairs = itertools.combinations(my_list, 2)

for pair in pairs:
    print(pair)

# Output: (1, 2), (1, 3), (1, 4), (2, 3), (2, 4), (3, 4)

The itertools.combinations() function is a powerful tool for generating all the possible combinations of items from a list. It can be used to solve a variety of problems, such as finding all the possible pairs of numbers from a list or all the possible combinations of items from a list.