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Coronavirus disease 2019 The Coronavirus runs around the world and causes many changes in our everyday lives. Correct information is important so that people behave well. What are good sources? World Health Oranization: Hands down the source I would trust most Johns Hopkins University Video: Kurzgesagt German Sources Robert Koch Institut Bundesregierung Informationen … Read More »

Code Golf: Brackets Check Write a function check_bracket_validity which takes a sequence of brackets as input and determines if it is valid. A sequence is valid, iff: All opened brackets close Brackets come in pairs - only what was opened can be closed again The 3 styles which should be supported are: Round brackets: ( and … Read More »

Software Architecture My mentee recently asked me what software architecture is. How do you draw an architecture diagram? What is a bad one and how do I learn to draw good ones? The software architecture gives a very high-level overview of a software system. Typical Components A software architecture tries to solve … Read More »

Migrate to Python 3 When I gave a Python Packaging Course, I advised my students to always use Python 3. After all, Python 2 is dead. But one student said she had to use Python 2 as there is a package she definitely needs to use. And it's Python 2 only. What can one … Read More »

Larget Continuous Sub-Array I recently taught a course about improving code for performance. An obvious performance improvement is to not execute unnecessary operations. I lacked a good example when I gave the course, but here is one: Find value of the largest continuous sub-array of fixed length in a huge array. This is … Read More »

File Compression I'm currently creating a backup of my domain martin-thoma.de. It is pretty small, but the MySQL database behind it grew extremely as I stored every drawing from write-math.com in there. For this reason, I want to store that specific table in a compressed way. But which compression format … Read More »

Matrix Multiplication: 2020 Update In 2012 I wrote a series of articles about matrix multiplication. Now I'm preparing a course about speeding up Python. For this reason I need an example of code that is fairly simple to understand and can be optimized. So let's update the results of my old articles :-) The code … Read More »

Current Python Versions Which Python versions should my library support? For which version should I develop my web service / application? For the second question, I like to never take a x.y.0 version. Let them get the patches out first. Lifecycle of cPython I've asked which CPython versions get support right now … Read More »

Python Packaging Course The Python Environment is old. Python development started before the internet. Naturally, such a grown environment is messy: Python Environment In this course, you will learn the details about Python packaging and how all of the tools related. Application Types Library: Should be included in other code. It will never … Read More »

Virtual Environments A virtual environment is an isolated Python environments. It has it's own installed site-packages which can be different from the systems site-packages. TL;DR: pipenv is your friend; it allows you to forget about the others. virtualenv virtualenv was created by Ian Bicking. The first version on PyPI is from … Read More »