Installation

Installation#

Important

If you are taking the course again please see Appendix C: If you are taking the course again for how to update.

Need help?

If you run into issues following the guide you can always ask in the course Discord (invitation link). In addition, DTU offer campus-wide python help on pythonsupport.dtu.dk, and their Discord channel is often a better place for unusual/platform-specific issues.

Installation instructions 2025

The course software supports the following python versions:

Note

All tests are known to work for the supported python versions. However, problems are often specific to certain computers/operating systems. Python 3.8 will not work.

  • Python 3.9

  • Python 3.10

  • Python 3.11 Recommended

  • Python 3.12 Recommended

  • Python 3.13 Experimental

This means that the course code and libraries is tested to be compatible on these versions.

Do I have to use Miniconda?

Python comes in different flavors: If for instance you are using MacOS, you can either download python from their website (https://www.python.org), or you can use the version of python that is installed on your computer already. So what to do?

In reality I would expect nearly any of the supported python versions to work, but one some platforms (Windows) you may for instance have to require you to install an external program such as swig.

This guide recommend that you use the miniconda-version of python which provides the python package management tool conda. miniconda will take care of external dependencies and to my knowledge provides by far the simplest installation process; furthermore, all introduction courses at DTU recommend that you use miniconda and offer centralized support (pythonsupport.dtu.dk).

Regardless of this some may prefer to not use miniconda. Here are my comments on different platforms/recommendations:

Windows:

On windows, I recommend that you use conda and otherwise follow the guide below to avoid problems with Farama gymnasium.

Linux:

Linux is very lenient. If you don’t like conda you can use regular python and pip install the packages, and everything will probably work out well

MacOS:

As far as I know this is similar to Linux, but I don’t use MacOS myself.

Finally, Anaconda will probably work just as well as Miniconda, however it takes up more space.

Step 1: If you already have conda and VS Code#

If you have already installed miniconda and VS Code using the guide on pythonsupport.dtu.dk you probably don’t have to do it again.

Note

If you are using an old version of conda and are having problems with numpy please check out Problem with _numpy_core.

In this case first try to update miniconda and python using:

conda install conda>=25.1.1
conda update python

in a terminal. I recommend that you use the terminal in VS Code. Then test that you have conda version 25.1.1 or later using:

conda --version

If this works skip to Step 3: Download the exercises. Otherwise it is probably best that you re-install miniconda.

Step 2: Install miniconda and VS Code#

TL;DR: Follow the guide on https://pythonsupport.dtu.dk/install/linux/manual.html. Here is an overview:

Step 3: Download the exercises#

Warning

You can put the 02465students-folder any place you like, but once you have completed the following steps you should not move or rename the folder for the remainder of the course as this will confuse Python. If you do move or rename the folder, you should re-do Step 6: Install the course software.

In this step you will download the course software to your computer.

Download the course toolbox as a zip-file:

After these steps you should end up with a folder called: 02465students containing the source code.

Step 5: Open VS Code#

  • Open VS Code

  • Open the folder 02465students you created before by using File ‣ Open Folder…. Open the folder in the file navigator and press the Open button

  • Start a new terminal using Terminal ‣ New Terminal

  • Type conda in the command line to check it works.

    • If this does not work try to restart your computer.

    • If it still does not work conda is not installed correctly in the previous step. Use google, a TA, or pythonsupports discord to get help

Step 6: Install the course software#

In the terminal you created in the previous step type:

conda env create -f environment.yml

Tip

If you don’t like that name irlcenv you can change it by editing environment.yml.

This will create a conda environment called irlcenv.

Select your environment in VS Code. To do this open the command pallet using ctrl+Shift+P, type Python: Select Interpreter, and select your environment (irlcenv) from the list. You can also see/select the environment in the lower right corner of VS Code.

Hint

You can always activate an environment in a terminal by typing:

conda activate irlcenv

When you activate the environment you will notice that the terminal begins with (irlcenv). If this is not the case you should use the command above to re-activate it. You can learn more about environments here.

Open a new terminal using Terminal ‣ New Terminal. Check that it says (irlcenv) in the left of the terminal.

Finally verify the installation by running this code in terminal:

python -c"import irlc; import gymnasium; print(gymnasium.__version__)"

If this code prints out 1.0.0 (or higher) you should be all set

Making sure your files are up to date#

Updating your files

To ensure that the course exercises work with the most recent versions of the libraries we use I will upload the exercise code during the course. I have written a small python script to update the files, irlc/update_files.py. You can run it like a normal file, or from the terminal:

python -m irlc.update_files

Note

The file will check your version of the toolbox against the most recent version on gitlab. It will then

  • Replace any files you are missing

  • Overwrite the tests for the weekly exercises and projects

It will not overwrite your solutions to the exercises and projects. If you may have changed a file and wish to reset it, just delete it from your computer and run update_files.py to update.

Known Issues#

Even though the installation worked for the TAs and me you might experience problems specific to your system. This guide will try to keep track of common problems and their solution

Problem with _numpy_core#

If you are using an existing version of conda you might get problems involving numpy core (I don’t have the error). This occurs because the current version of numpy is version 2.0 (or later) and older versions of conda install version 1.26. To check your current version of numpy run:

python -c"import numpy; numpy.__version__"

If this is older than 2.0.1 then run

conda install numpy>=2.0.1

Since this problem involves older versions of conda you might have to re-install miniconda if the problem persists.

Cannot find file#

You get an error such as:

ModuleNotFoundError: No module named 'irlc.exam.midterm2023a.question_pid'

First check that the file you are trying to run exists (in this case irlc/exam/midterm2023a/question_pid.py). If this is the case, you probably have two copies of the irlc-package, and the file is not located in the one you installed in Step 6: Install the course software.

Solution: To check where you installed irlc, run the following command from the VS Code terminal

Note

on MacOS, assuming you normally run programs with python3, use: python3 -c"import irlc; print(irlc.__path__)"

python -c"import irlc; print(irlc.__path__)"

On my computer this will print out ['/home/tuhe/Documents/02465students/irlc']. Then make sure the file you are trying to run is located in this directory, i.e. as /home/tuhe/Documents/02465students/irlc/exam/midterm2023a/question_pid.py.

Windows#

This application failed to start because it could not find or load the Qt platform plugin “windows”

Try these commands in the VS Code terminal:

pip uninstall pyqt5
conda install pyqt

If this fail to work see this thread.

Linux: If the right-click menu looks bad#

If the right-click menu looks bad (i.e., it is to big etc) you can fix it as follows:

  • press ctrl+Shift+P in VS Code

  • Search for and select Preferences: Open workspace settings from the drop down.

  • Under the User tab, search and find Window: title bar style and change it to custom.

  • Restart VS Code and enjoy that the menus fit on screen.

Appendix A: Setting up Pycharm#

If you wish to use Pycharm instead of VSCode, this is how I recommend you set it up. To get started follow the previous guide but feel free to skip the bits about install VS Code, obviously.

  • Install Pycharm community edition

  • Start pycharm and create a new project. The name can be anything you like such as 02465rl

  • The root of the project can be anything – we are going to fix that later.

  • Select the interpreter you installed. If you followed the above guides, it should probably be under System interpreter. Look under Conda from the drop-down menu.

  • Create project and wait for pycharm to load. Then open settings using ctrl+alt+s (or use the file menu)

  • Under project: <projectname> select Interpreter

  • Check you got the main packages you installed such as gym. If not, select an interpreter from the list. If the python version you installed is not show, use show all from the dropdown and you can add/configure the one you installed

  • Under project: <projectname> select Project structure

  • Select Add project root. Navigate to and add the 02465students folder.

  • again in the settings dialog, under Tools select Python integrated tools. Then change Default test runner to just Unittest.

  • You are now done. You should be able to run and debug files. Note that pycharm will not allow you to run files while it is indexing your packages (check progress bar in lower right corner)

In case Pycharm runs your tests twice (and first time fails)#

Recent versions of pycharm use something called Pytest to set up and evaluate the test. Pytest has a bug where it will run the same test twice but in a different way, leading the test to crash in the first go. A way to tell this has happened is to look at the error message and see if it mentions pytest near the beginning.

The way to fix that is to disable pytest and use regular python unittest instead. This is easy:

  • Click File then Settings..

  • Click Tools and select Python integrated tools

  • From the dropbox Default test runner select Unittest (see screenshot)

Selecting your test runner.

This will mean new tests are no longer run by Pytest, but Pycharm has a habit of remembering previous run configurations so if the problem occurs again, go in the top-right corner, click the drop-down menu left of the run-button (see screenshot below) and select Edit Configurations. This will open a window with all configurations. From the menu on the left, find all configurations that mention tests, select them, and press the small minus sign to delete them – don’t worry if you delete one too many, pycharm will recreate them. (see screenshot)

Deleting bad configurations.

Appendix B: Python 3.13#

Python 3.13 is the most recent version of python. Although it works fine on the platforms I have tested, it is my experience that the newest version of python can have platform-specific issues with regards to complex packages such as pygame or gymnasium so be on the lookup if you encounter strange errors. I will list problems and solutions here.

Appendix C: If you are taking the course again#

The course toolbox is continuously updated and therefore it is important that you have the most recent version of the exercise files.

To do this, make a backup of your 02465students-directory by e.g. renaming it to 02465students-backup.

Then re-do the step Step 3: Download the exercises to get a fresh copy of the course toolbox which you can call 02465students again. Most of your solutions to the exercises will work this year, but you should copy-paste your solutions into the updated .py-files just to be sure; be particularly vigilant with the projects.

Finally you need to update your python packages. If you are using conda, the simplest option is to re-do the step Step 6: Install the course software, which will create a new environment with a fresh copy of all packages.

Alternatively, you can update packages manually when/if you encounter problems. To update the pip packages use:

pip install -r requirements_pip.txt --upgrade

To update a package installed using conda use:

conda update conda
conda update --all

When done check that you got gymnasium version 1.0.0 or later using:

python -c"import gymnasium; print(gymnasium.__version__)"

Appendix D: Install the course software without using Conda#

Feeling adventurous are we?

  • Don’t

  • Install swig from https://www.swig.org/download.html

  • Download and install python 3.12 from https://www.python.org

  • Install VS Code, the VS Code python plugin, and to download the course software

  • Run these commands in the terminal:

    python -m pip install -r requirements_pip.txt
python -m pip install -r .vscode/requirements_conda.txt

  • Perhaps everything works; if not use google. Conda is not magic so there is a way to fix the problems you might encounter but it will require a bit of reading

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