To test multiple variables x, y, z against a value v, use the set membership operation v in {x, y, z} that leverages the in keyword to check if the value v matches any value in the set {x, y, z}. The return value is a Boolean and the runtime complexity is O(1) to check … Read more
Summary: To merge two dictionaries dict1 and dict2 in a single expression, use the dictionary unpacking feature z = {**dict1, **dict2}. This creates a new dictionary and unpacks all (key-value) pairs into the new dictionary. Duplicate keys are automatically resolved by this method. Exercise: Which of the duplicated entry ends up in the dictionary? Other … Read more
Problem: Given a JSON object. How to pretty print it from the shell/terminal/command line using a Python one-liner? Minimal Example: You have given the following JSON object: And you want to get the following print output: How to accomplish this using a Python one-liner? Method 0: Python Program + json.dump The default way to accomplish … 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 beginner programmers have a problem with the so-called TypeError, they wonder what they are doing wrong. Here’s an example: Exercise: Run the script and reproduce the error! Study this article to learn how to fix it! This article will answer every question that beginners may ask about this topic. About The TypeError Before showing … Read more
Problem: How to create a Python object in a single line of code? And how can you associate custom properties to this object in the same line? Example: Say, you want to do something like this pseudocode snippet: However, you cannot do the same in Python because this would create a dictionary: This raises an … 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
How do the Boolean and and or operators work in the context of Python one-liners? You may know the standard use of the logical operators applied to Boolean values: But there’s more to these operators that only experts in the art of writing concise Python one-liners know. For instance, the following use of the or … 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
URL encoding “is a method to encode information in a Uniform Resource Identifier (URI)”. It is also called Percent-encoding because percentage symbols are used to encode certain reserved characters: ! # $ % & ‘ ( ) * + , / : ; = ? @ [ ] %21 %23 %24 %25 %26 %27 %28 … Read more
Python has several built-in data structures such as Lists, Sets and Dictionaries (check out the articles!).In this article, you’ll learn everything you need to know about tuples including real world examples. A Python tuple is an immutable, ordered, and iterable container data structure that can hold arbitrary and heterogeneous immutable data elements. Tuple Motivating Example … Read more
Do you dream of creating your own coding business online as a web developer, Python freelancer, or programmer? Creating your coding business on the side is one of the best ways to test the waters and build crucial business skills before you fully commit to your new freelancing venture. Here are the eight steps to … Read more