# Month: September 2019

## NoStarch Author Questionnaire for Upcoming Book “Python One-Liners”

Today, I filled in the author questionnaire for any author who publishes a book with the international techbook publisher NoStarchPress. I share this article because (1) other authors may be interested in how the concrete questions look like, and (2) Finxter readers may be interested in the upcoming book “Python One-Liners” (to appear in 2019) …

## A 3-Min Primer on Python Decorators

Say, you are working for a large bank. Your hacker colleague implemented a magic function that uses SSH to log into the bank’s core server (written in COBOL which you don’t know at all), analyzes the CPU usage over the last 24 hours, and returns the result as a cryptic string value. Your boss asks …

## A Python Implementation of NumPy Cumsum

You may know the np.cumsum() function from the NumPy library that calculates the cumulative sum of a given NumPy array. How can we implement this function in Python? Studying this will not only show you how the NumPy cumsum function works, but it’ll also make you a better coder because it contains many important concepts …

## Python Numpy 101: How to Calculate the Row Variance of a Numpy 2D Array?

You can play with the following interactive Python code to calculate the variance of a 2D array (total, row, and column variance). Here’s another practical example: What is the output of this puzzle?*Advanced Level* (solution below) Numpy is a popular Python library for data science focusing on arrays, vectors, and matrices. This puzzle introduces a …

## Focus on One Thing. But What’s the Thing?

This article does not give you the standard advice: do what you love. You should love what you do but you don’t necessarily have to do what you love. Oftentimes, the love comes by being successful in a thing. But to be successful, you have to differentiate yourself in the 21st century. In business, it’s …

## How do You Slice and Index Multidimensional Arrays in Numpy?

Python’s library for data science, NumPy, allows you to slice multidimensional arrays easily. For multi-dimensional slices, you can use one-dimensional slicing for each axis separately. You define the slices for each axis, separated by a comma. Here are a few examples drawn from my comprehensive NumPy tutorial. Take your time to thoroughly understand each of …

## How to Get Rid of Python’s Map Function With List Comprehension

You may have read that Python’s godfather, Guido van Rossum, doesn’t like the map() function too much. He argues that it can be easily replaced with list comprehension which is not only faster but also more readable and shorter. Here’s an example: You can solve the puzzle on the interactive Finxter app before reading on …

## What is a Career in Computer Programming Like?

All programming is not created equal. Having said this, I don’t know a single programmer who regrets his choice of learning to program. With growing automation, programming becomes more and more a skill that is at the heart of many tasks in our society. No matter whether you work in the medicine, logistics, retail, or …

## How Does One Become a Freelance Coder?

Becoming a freelance coder is both easy and difficult. It’s easy because everybody can do it within a day or so. And it’s hard because most people fail miserably because they don’t know the right way of approaching this. Maybe you are interested in coding, or maybe you are already very good at coding. But …

## How Python Freelancing Helped Me Create a Thriving Coding Business on the Side

I’m a full-time online business owner working in the Python education space. But I started my career by working as a doctoral computer science researcher at the University of Stuttgart, Germany. While I was working there, I started my online business by finishing a few Python freelancing jobs. Creating a side-business helped me greatly in …

## Upwork vs Fiverr — Where to Sell Your Freelancing Services as a Coder?

So you want to participate in the booming “gig economy” creating an additional income stream by working from home? Members of my Python Freelancer Course ask this question a lot: what’s the best marketplace to sell your coding skills: Upwork.com or Fiverr.com? This is a multi-dimensional decision problem, but I have a clear preference. Read …

## How Do You Deal with International Sales Taxes when Creating Your Online Course with Teachable, Podia, or Thrive Apprentice?

I am not an attorney and this should not be taken as legal advice. It’s just based on my experience as a course creator. Teachable does not collect state sales taxes for you. They also don’t collect taxes for all international sales. If a user from Japan buys your course, you are responsible for paying …