How to Find Common Elements in Two Python Lists?

How to Identify and Return Matching Elements from Two Lists in Python

When working with lists, it's often necessary to compare them and identify the values that appear in both. In Python, there are several approaches to achieve this task. One straightforward method is to utilize the intersection of sets to find common elements:

a = [1, 2, 3, 4, 5]
b = [9, 8, 7, 6, 5]

result = set(a) & set(b)
print(result)  # Output: {5}

In this example, the sets a and b are created and their intersection is computed using the & operator. The result is a set containing the matching value, {5}.

For cases where the order of elements matters, a list comprehension can be employed:

a = [1, 2, 3, 4, 5]
b = [9, 8, 7, 6, 5]

result = [i for i, j in zip(a, b) if i == j]
print(result)  # Output: [5]

Here, a zip object is created to iterate through both lists simultaneously. The list comprehension filters the pairs of elements comparing them with the == operator, and returns the matching values in order. This approach works effectively for lists with the same number of elements.

By leveraging the respective capabilities of sets and list comprehensions, you can efficiently identify and return matching elements from two lists in Python, depending on the specific requirements of your task.

The above is the detailed content of How to Find Common Elements in Two Python Lists?. For more information, please follow other related articles on the PHP Chinese website!