Python’s built-in all(x) function takes one iterable as an argument x such as a list, tuple, or dictionary. It returns True if all iterable elements evaluate to True using implicit Boolean conversion, otherwise it returns False. If the iterable is empty, all() returns True because the condition is satisfied for all elements. Argument x -> … Read more
Python comes with many built-in functions you can use without importing a library. The following table goes over all built-in functions in alphabetical order. If you click on any of the provided links, you’ll find an in-depth article with a short explainer video on the Finxter blog to help you improve your skills. Just follow … Read more
This tutorial taken from my upcoming programming book “From One to Zero” (NoStarch, 2021) will show you how to write great comments. While most online tutorials focus on a bullet list of commenting tips, we dive deeper into the meat exploring the underlying reasons for the commonly recommended commenting principles. So, let’s get started! Code … Read more
The line plot is the most iconic of all the plots. To draw one in matplotlib, use the plt.plot() function and pass it a list of numbers used as the y-axis values. Per default, the x-axis values are the list indexes of the passed line. Matplotlib automatically connects the points with a blue line per … Read more
Writing code in Python is not always an easy task. Often writing “perfect” code without any errors is nothing more than a coder’s daydream. Allow me to introduce you to a little function programmers use to debug their code called the breakpoint() function. Now there are several tools a programmer can use in their coding … Read more
You may encounter a special ValueError when working with Python’s math module. Python raises this error when you try to do something that is not mathematically possible or mathematically defined. To understand this error, have a look at the definition of the domain: “The domain of a function is the complete set of possible values … Read more
The np.polyfit() function, accepts three different input values: x, y and the polynomial degree. Arguments x and y correspond to the values of the data points that we want to fit, on the x and y axes, respectively. The third parameter specifies the degree of our polynomial function. For example, to obtain a linear fit, … Read more
Want to calculate the variance of a column in your Pandas DataFrame? In case you’ve attended your last statistics course a few years ago, let’s quickly recap the definition of variance: it’s the average squared deviation of the list elements from the average value. You can calculate the variance of a Pandas DataFrame by using … Read more
Have you ever had a string and wanted to make it a certain length by adding zeros to it? You could type it out. But we’re programmers, we hate typing! Surely there must be a way to code this? To pad zeros to a string, use the str.zfill() method. It takes one argument: the final … Read more
Question: Is it possible to call a function inside a list comprehension statement? Background: List comprehension is a compact way of creating lists. The simple formula is [expression + context]. Expression: What to do with each list element? Context: What elements to select? The context consists of an arbitrary number of for and if statements. … Read more
Do you encounter this stupid error? You’re not alone—thousands of coders like you generate this error in thousands of projects every single month. This short tutorial will show you exactly why this error occurs, how to fix it, and how to never make the same mistake again. So, let’s get started! Python throws the TypeError … Read more
The most Pythonic way to convert a list of floats fs to a list of integers is to use the one-liner fs = [int(x) for x in fs]. It iterates over all elements in the list fs using list comprehension and converts each list element x to an integer value using the int(x) constructor. This … Read more