Are you ready to take your Python knowledge to the next level? Let’s have a little fun with the inputs. Only instead of having you enter your name, we’ll work with numbers. It’s a nice, simple calculator. You enter in two numbers and it adds them together to give you an answer. Simple, right? Well, … Read more
Python provides fantastic string formatting options, but what if you need greater control over how values are presented? That’s where format specifiers come in. This article starts with a brief overview of the different string formatting approaches. We’ll then dive straight into some examples to whet your appetite for using Python’s Format Specification Mini-Language in … Read more
Problem: Given two variables a and b. Use a single line of Python code to swap the variables to assign the value of a to b and the value of b to a. Example: Say, you have to integers a=21 and b=42. You want to swap the variables so that a=42 and b=21. How to … Read more
Problem: How to Parse a JSON object as a Python One-Liner? Example: Say, you have pulled a JSON object from a server using the curl command: Source How to parse the resulting JSON object and extract, say, the value “Netherlands” associated to the “country” key? Solution: The following one-liner accomplishes this: The command consists of … Read more
Many Python coders—even at intermediate skill levels—are often puzzled when it comes to the asterisk character in Python. What does it mean? How does it work? What’s it purpose? This article answers all of those questions and more. After studying this article, you will have a solid understanding of the asterisk operator * in Python—and … Read more
This interesting code snippet was brought to my attention by Finxter reader Albrecht. You’d guess that the for loop goes from i=250 to i=259, each time incrementing a and b. As Python creates one integer object to which both names refer, the command a is not b should always be False. Thus, the result is … Read more
To break one line into multiple lines in Python, use an opening parenthesis in the line you want to break. Now, Python expects the closing parenthesis in one of the next lines and the expression is evaluated across line boundaries. As an alternative, you can also use the backslash \ just in front of the … Read more
Problem: Given the contents of a text file. How to search and replace a specific string or line in the file? Example: Let’s consider the following example where you want to replace the highlighted (bolded) text parts. Text in the file before replacing a line: There was an idea to bring together a group of … Read more
Problem: You use Python in a terminal and you want to replace a string ‘example’ in a text file file.txt: Your goal is to accomplish the following text: In particular, you want to open the file, replace the text, and rewrite the result into the file—all in a single line of Python code! Can a … Read more
Summary: To match a pattern in a given text using only a single line of Python code, use the one-liner import re; print(re.findall(pattern, text)) that imports the regular expression library re and prints the result of the findall() function to the shell. Problem: Given a string and a regular expression pattern. Match the string for … Read more
Most computer scientists, programmers, and hackers don’t even know the meaning of the word “Quine” in the context of programming. So, first things first: What is a Quine? Roughly speaking, a quine is a self-reproducing program: if you run it, it generates itself. Here’s a great definition: :quine: /kwi:n/ /n./ [from the name of the … Read more
Problem: Given a string and a filename. How to write the string into the file with filename using only a single line of Python code? Example: You have filename ‘hello.txt’ and you want to write string ‘hello world!’ into the file. How to achieve this? In this tutorial, you’ll learn four ways of doing it … Read more