Python’s creator Guido van Rossum doesn’t like the map() function because it can be easily replaced with list comprehension which is not only faster but also more readable and shorter. Map() vs List Comprehension Here’s an example: Both lists list_1 and list_2 contain the same data: a series of squared values [0, 1, 4, 9, … Read more
Problem: Given a list of lists representing a data matrix with n rows and m columns. How to sum over the rows of this matrix? In this article, you’re going to learn different ways to accomplish this in Python. Let’s ensure that you’re on the same page. Here’s a graphical representation of the list of … Read more
Problem: Given a list of lists representing a data matrix with n rows and m columns. How to sum over the columns of this matrix? In this article, you’re going to learn different ways to accomplish this in Python. Let’s ensure that you’re on the same page. Here’s a graphical representation of the list of … Read more
Many coders who are just starting with Python struggle with a thorough understanding of Python loops: ” I struggle a lot with for loops, well all types of loops! “ — Leonardo, Finxter “Coffee Break Python” Email Subscriber Every time you want to repeat a certain behavior, you use loops. For example, if you want … Read more
Problem: You have a list of lists and you want to calculate the average of the different columns. Example: Given the following list of lists with four rows and three columns. You want to have the average values of the three columns: There are three methods that solve this problem. You can play with them … Read more
What’s the best way to remove duplicates from a Python list of lists? This is a popular coding interview question at Google, Facebook, and Amazon. In this article, I’ll show you how (and why) it works—so keep reading! How to remove all duplicates of a given value in the list? Method 1: Naive Method Algorithm: … Read more
6 min read How to read data from a .csv file and add its column or row to the list? There are three main ways: Option 1 (the quickest): use the standard library Option 2 (the most preferred): use pandas.read_csv() Option 3 (optional): use csv.reader() Short answer The simplest option to read a .csv file … Read more
Python is one of the best and well-reputed high-level programming languages since 1991. It is best for server-side development, AI, scripting, software development, and math. It works well on multiple platforms like Mac, Linux, Windows, and Raspberry Pi. Developers use Python code editor’s software to program and debug the code easily. By using Python IDE, … Read more
Short answer: You can remove all empty lists from a list of lists by using the list comprehension statement [x for x in list if x] to filter the list. In the following, you’ll learn about the two methods using list comprehension and the filter() function to remove all empty lists from a list of … Read more
Short answer: To print a list of lists in Python without brackets and aligned columns, use the ”.join() function and a generator expression to fill each string with enough whitespaces so that the columns align: I’ll explain this code (and simpler variants) in the following video: As an exercise, you can also try it yourself … Read more
[20-SEC SUMMARY] Given a list of list stored in variable lst. To flatten a list of lists, use the list comprehension statement [x for l in lst for x in l]. To modify all elements in a list of lists (e.g., increment them by one), use a list comprehension of list comprehensions [[x+1 for x … Read more