Short answer: To flatten your list of list lst, use the nested list comprehension [x for l in lst for x in l] to iterate over all nested lists (for l in lst) and over all their elements (for x in l). Each element x, you just place in the outer list, unchanged. When browsing … Read more
In Python, there are always multiple ways to accomplish the same thing—but with subtle differences in the side effects. A great coder will always choose the most effective way for the problem at hand. This tutorial shows you six different ways to add elements to a list in Python. In a nutshell, the different ways … Read more
The Python built-in list data type is powerful. However, the NumPy array has many advantages over Python lists. What are they? Advantages NumPy Advantages Python Lists Multi-dimensional Slicing Library-Independent Broadcasting Functionality Intuitive Processing Speed Less Complicated Memory Footprint Heterogeneous List Data Allowed Many Convenience Methods Arbitrary Data Shape (Non-Square Matrix) Let’s dive into the most … Read more
Do you want to convert a Python set to a list? Use the list(…) constructor and pass the set object as an argument. For example, to convert a set of strings friends into a list, use the code expression list(friends). Here’s an example code snippet that converts the set to a list using the list(…) … Read more
Do you have a list but you want to convert it to a Python set? No problem! Use the set(…) constructor and pass the list object as an argument. For example, if you have a list of strings friends, you can convert it to a set using the call set(friends). Here’s an example code snippet: … Read more
In this tutorial, you’ll learn the runtime complexity of different Python operations. Then, you’ll learn how to calculate the complexity of your own function by combining the complexity classes of its constituents. This is called “static analysis” The tutorial is loosely based on (source) but it extends it significantly with more practical examples, interactive snippets, … Read more
To add an element to a given Python list, you can use either of the three following methods: Use the list insert method list.insert(index, element). Use slice assignment lst[index:index] = [element] to overwrite the empty slice with a list of one element. Use list concatenation with slicing lst[:2] + [‘Alice’] + lst[2:] to create a … Read more
Short answer: To find the minimal list in a list of lists, you need to make two lists comparable. How? With the key argument of the min() function. The key argument is a function that takes one input (a list) and returns one output (a numerical value). The list with the smallest numerical value is … Read more
Short answer: To find the maximal list in a list of lists, you need to make two lists comparable. How? With the key argument of the max() function. The key argument is a function that takes one input (a list) and returns one output (a numerical value). The list with the largest numerical value is … Read more
This tutorial shows you how to group the inner lists of a Python list of lists by common element. There are three basic methods: Group the inner lists together by common element. Group the inner lists together by common element AND aggregating them (e.g. averaging). Group the inner lists together by common element AND aggregating … Read more
Short answer: To filter a list of lists for a condition on the inner lists, use the list comprehension statement [x for x in list if condition(x)] and replace condition(x) with your filtering condition that returns True to include inner list x, and False otherwise. Lists belong to the most important data structures in Python—every … Read more
In Python, __doc__ is a special attribute that stores a string defining the documentation for a module, class, method, or function. It’s typically derived from a docstring — the first statement in the defined block, enclosed in triple quotes — providing a convenient way to access descriptive texts about the code’s functionality. You can define … Read more