The single underscore in Python “_” is used to either make a variable different from a Python keyword such as in float_=8, or to indicate that it should be used in a private context such as in _var=8. The double underscore in Python “__” (called “dunder“) is used to make an instance attribute or method … Read more
Problem Formulation Given a timestamp x such as the current time and a time interval marked with start and end timestamps. Goal: Create a function that checks whether the given timestamp falls in the interval [start, end], so that x>=start and x<=end. Constraints: If the interval is empty when start >= end and x != … Read more
The pass statement does nothing when executed. You can use it as a placeholder for future code so that you can focus on the high-level structure first and implement the details later. For example, functions, loops, class definitions, or if statements require at least one statement in their indentation block. Think of the pass statement … Read more
Problem Formulation: Given a string my_string. Find the number of characters of the string! For example, the string “what is my length?” must yield integer 18 because it has 18 characters. Here are three examples of our desired outputs: Solution: Before we dive into alternatives, here’s the quick answer to this question. To get the … Read more
A question frequently asked in programming forums concerns the use and iteration of dates in Python. Today I wish to introduce the basics of the datetime module in Python, which will allow us to output a range of dates, given a date input and the number of days needed. We will also look at creating … Read more
This tutorial explores the ways one can check if a variable is a class. The direct way to check if a variable is a class, is to use the isclass() runtime service, from Python’s inspect module. Use isclass() in conjunction with Python’s isinstance() built-in function, to examine a variable. Both of these return a Boolean … Read more
Do you train for your upcoming coding interview? This question was asked by Google as reported in multiple occasions by programmers all around the world. Can you solve it optimally? Let’s dive into the problem first. Problem Formulation Given an integer array or Python list nums and an integer value k. Find and return the … Read more
To print a percentage value in Python, use the str.format() method or an f-string on the format language pattern “{:.0%}”. For example, the f-string f”{your_number:.0%}” will convert variable your_number to a percentage string with 0 digits precision. Simply run those three basic statements in your shell: your_number = 0.42 percentage = “{:.0%}”.format(your_number) print(percentage) As a … Read more
Iterables and iterators are everywhere in Python. We usually aren’t aware of the iterators because the syntax of python hides them from us. Almost every time we manipulate a sequence type (strings, lists, tuples, sets, arrays, etc.), we’re using an iterator behind the scenes. An iterable represents a sequence of values each of which is … Read more
A Python class attribute is a variable that belongs to a class, not an individual instance, and is shared among all instances. An instance attribute is a variable that belongs to exactly one object. An instance attribute is defined inside the __init__() method by using the reference to the instance self, whereas a class attribute … Read more
Python provides three ways to stop a while loop: The while loop condition is checked once per iteration. If it evaluates to False, the program ends the loop and proceeds with the first statement after the loop construct. The keyword break terminates a loop immediately. The program proceeds with the first statement after the loop … Read more
When mentally approaching this problem, you may be tempted to utilize a “for loop”. I admit that’s how my mind was working: iterate through the list one element at a time and check for empty strings. If it’s empty, remove it. Repeat. Please join me in today’s topic on how to remove empty strings from … Read more