Articles about programming

1. Writing C in 2024

   To learn how it works and because I don’t use Java, I decided to port professor Michael Pound’s implementation of the Enigma machine and the fitness and analysis code.

   The initial port was done to Python. Unfortunately, this is one instance where Python was rather slow because of the large amount of settings that need to be tried.

   So I decided to port it to C instead.

2. Profiling Python scripts(6): auto-orient

   This is the fifth in a series of articles that covers analyzing and improving performance bottlenecks in Python scripts. The program calculix-orient is a helper program that automates the asignment of local coordinate systems for anisotropic finite elements. It is designed to work together with CalculiX.

3. Profiling with pyinstrument

   After having used the built-in tracing profiler cProfile for a while now, I came across the statistical (sampling) profiler pyinstrument.

   A statistical profiler does not influence the runtime of the program as much as a tracing profiler as cProfile does. Additionally, pyinstrument shows the result in a different way from cProfile.

   So in this article, I will be profiling my repotool program. This program helps me maintain a mirror of FreeBSD packages that I use.

4. From python script to executable with cython

   Recently I saw that you could convert python scripts into executable with the help of cython, and I had to try that.

5. On Python speed

   As an engineer, I write a lot of small python programs as tools for specific tasks. Generally, these are not large programs. Most of them are below 100 lines of code (“LOC”, as measured by cloc), although there are a few in the 300−400 LOC range.

   In this article, I will present some observations about these, and draw some conclusion from them.

6. Python 3.11 speed comparison with 3.9

   Since Python 3.11.0 came out recently, I wanted to compare its speed with 3.9.15 on some of my own “benchmark” programs.

   Both versions are in the default configuration as built by the FreeBSD ports system.

   TL;DR Python 3.11 yielded speed improvements in the order of 25% in my tests.

7. Getting the first or last item from a dictview without a list

   In this article we will discuss a faster and more efficient way to get only the first item from a view object in Python.

8. Examining an OpenSSH ECDSA public key

   Intrigued by this question, I investigated the structure of an OpenSSH ECDSA public key.

9. Python & standard output redirection on ms-windows

   Redirecting standard output of the Python script on ms-windows can cause strange crashes because of encoding differences.

10. Profiling Python scripts (5): ent_without_numpy

    This is the fifth in a series of articles that covers analyzing and improving performance bottlenecks in Python scripts. The program ent_without_numpy.py is a lot slower than the version that uses numpy. The performance of ent_without_numpy.py is the topic of this article.