# Count Equal Pairs in List in Python (2 Examples)

In this Python article, you will learn how to count the pairs in a list.

The tutorial contains the following content:

Let’s dive right in!

## Example Data

The first step in this tutorial will be creating an example list:

```my_list = ["car", "bicycle", "car",
"metro", "bus", "plane",
"bicycle", "car", "bus", "metro"]
print(my_list)
# ["car", "bicycle", "car",
#  "metro", "bus", "plane",
#  "bicycle", "car", "bus", "metro"]```

Have a look at the previous output! It prints my_list, which contains ten strings. In my_list, “car”, “bus”, “bicycle” and “metro” strings are repeated. Let’s see how to count all these duplicated elements!

## Example 1: Count Pairs in List Using Counter() Constructor

This example illustrates how to count the repeated items in a list using the Counter class of the collections module in addition to the use of sum() function. To do so, first, we need to import the collections module.

`from collections import Counter`

Now, we will plug my_list into the Counter() constructor and obtain the total number of pairs in our list using the values() method.

```sum(i // 2 for i in Counter(my_list).values())
# 4```

As shown, there are four repeated elements of strings in my_list.

## Example 2: Count Pairs in List Using set() Function & count() Method

It is also possible to count the pairs in a list using the built-in set() function and the count() method together. In addition to them, the `//` operator, which refer to floor division, is made use of as well.

```elements = set(my_list)
results = 0
for i in elements:
results += my_list.count(i) // 2

print(results)
# 4```

As shown, first, the set() function converts our list into a set. Then, we iterate through the elements on our list by counting and summing the largest integers obtained after dividing the counts by two. As a result, we get the number of four pairs, just as expected!

## Video, Further Resources & Summary

Do you need more explanations on how to count the number of pairs in a list in Python? Then you should have a look at the following YouTube video of the Statistics Globe YouTube channel.

Furthermore, you could have a look at some of the other tutorials on Statistics Globe:

This post has shown how to count the number of pairs in a list in Python. You can write in the comments section below if you have any additional questions.