AWS Certified Cloud Practitioner

I am not the first man who writes about that and shares his own experience but anyway would like to add some points from my side. Recently I have passed AWS CCP exam which is the foundational level…

Smartphone

独家优惠奖金 100% 高达 1 BTC + 180 免费旋转




How to efficiently use List Comprehensions in Python

With Code Implementation

Imagine you have a toy box full of different types of toys — cars, dolls, balls, and so on. Now, you want to pick out only the cars from the toy box and put them into another box. How would you do that?

In Python, we have a cool trick called “list comprehensions” that can help us with tasks like this. It’s like having a magical machine that automatically picks out the toys you want from the toy box and puts them into a new box for you!.

Here’s how it works:

Isn’t that amazing? 😄

So, instead of manually checking each toy and putting the cars into a new box, Python’s list comprehensions do it for you automatically. It’s a quick and efficient way to create new lists based on certain conditions.

Now you can use list comprehensions to do all sorts of cool things with your toys or any other type of data in Python! 🚗🎀🏀

List comprehensions are a concise and powerful feature in many programming languages, including Python. They provide a compact way to create new lists based on existing lists or other iterable objects. List comprehensions allow you to combine loops, conditional statements, and expressions into a single line of code.

In Python, the basic syntax of a list comprehension is as follows:

Fig 1.1 Basic Syntax of List Comprehension

Let’s break down the components of a list comprehension:

Here’s an example to illustrate the concept. Let’s say we have a list of numbers and we want to create a new list that contains only the even numbers multiplied by 2:

Output:

In this example, the expression num * 2 multiplies each even number by 2. The loop iterates over each item in the numbers list, and the condition num % 2 == 0 filters out the odd numbers.

List comprehensions provide a concise and readable way to create lists based on existing data, making the code more expressive and efficient. They are widely used in Python programming to simplify tasks involving list manipulation, filtering, and transformation.

Here are some reasons why and when you might want to use list comprehensions:

Here are a few examples to illustrate the usage of list comprehensions:

Fig 1.4 Examples of List Comprehensions operations

In summary, They enhance code readability, promote a functional programming style, and can improve performance in some cases.

List comprehensions follow a specific syntax that allows you to define the elements of the new list in a single line.

Here’s an example of how you can implement list comprehensions:

Fig 1.5 Example of List Comprehension

In the examples above, the expression inside the square brackets [ ] defines how each element of the new list is derived. The general syntax of a list comprehension is [expression for item in iterable if condition], where expression is the operation to be performed on each element, item is a variable representing each element of the iterable, and condition (optional) is used to filter elements based on a specific condition.

Add a comment

Related posts:

2 vs 4 spaces indentation for coding

Ever found yourself trying to decide if 2 or 4 spaces is best for your new code project? Great! Keep reading. I could save you the hassle of reading the entire post and tell you which of the two is…

Happy Easter Every Bunny

Wherever you are and whatever you are doing, my wishes for you are to be safe and to look forward to renewal and hope. The Easter story is about strength and endurance and resurrection. The current…