I had come across Crypto Pals web site a while ago (2015?). https://cryptopals.com/
I didn't have time to tackle the challenges then, but now I found some time to deal with Python a bit more.
#Why Python? I'm trying to learn a new language. (I have the following background in computer programming:
COMMODORE 64: BASIC V2 WINDOWS: GW BASIC, QUICK BASIC, ASSEMBLY, TURBO PASCAL, DELPHI, VISUAL BASIC, VBA, FORTRAN, C, C++, MATLAB LINUX : C, C++
I've done graphics codes in TP + ASM setup (own libraries).
I've done scientific computations (some CFD, some structural in Fortran and C/C++)
I've done engineering coding in Matlab scripts, and did automatic/batch simulations of Simulink models...
I enjoy using computer power to generate images, animations, and scientific/engineering results.