Pluggakuten has a subforum for Python where you can relatively quickly get help with all sorts of questions. Even university-level questions.
Project Euler 🇺🇸Project Euler has hundreds of problems that require mathematical and computational thinking. The problems can be solved with any programming language. Create an account to submit solutions.
Advent of Code 🇺🇸Every year since 2015, there is a Christmas calendar with very nice problems. Every day from December 1-25, a problem comes in two parts. The first week is the easiest. In the end, even professional programmers are challenged. All old problems remain.
open.kattis.com 🇺🇸🇸🇪Kattis is a judging system for programming competitions. Here you will find many programming problems of varying difficulty. From easy to very difficult. You get points for solved problems and there are ranking lists for counties, countries and universities. To get into the top 50 in Sweden requires a lot of work! The site's language is English but the site is from Sweden.
bebras.se 🇸🇪The Beaver is a competition in computational thinking for different ages, both in primary school and in high school.
csunplugged.org 🇳🇿On this page there are many resources for teachers, but also activities to do at home and challenges for students. Languages: Scratch and Python.
hjernekraft.org 🇸🇪Every year the First Lego League competition is held with Lego robots. A really fun competition that needs more attention in many parts of Sweden. It's easy to stumble into the Norwegian parts of the site but it's also available in Swedish.
hourofcode.com 🇸🇪Hour of Code is a project to get as many people as possible to try programming. Here you will find many one-hour exercises for beginners.
Kängurutävlingen 🇸🇪The Kangaroo is a mathematics competition for primary school. It is good to train in logical and spatial thinking to become good at programming.
progolymp.se 🇸🇪High School Nationals in programming. It can be a fun goal to participate here and try to solve some tasks. The best in Sweden get to go to IOI and to get there requires a lot of training.
scratch.mit.edu 🇸🇪Scratch is the most popular block-based programming language. Programming with blocks is perfect for beginners. It can be good to learn the basics of Scratch before Python for most people.
larslindehaven.wordpress.com 🇸🇪Lars Lindehaven's course in programming with Python. Even if you use Pythonlabbet, it can be good to read from a different perspective.