Data Analysis with Python 2021
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Frequently asked questions

Can I retake the exam to change my grade?

Yes, you could retake the exam another time before the end of the course to change your final grade, however, please do not register your credits if you plan to do that, and also let the instructor know about the situation so they can change your grade.

How to load a file that resides in the src folder?

TMC runs code from the project root. So for python to find file.txt, you need to pass it the folder as well. That is src/file.txt.

However, if you are requested to write a function, say f, that gets a filename as a parameter, then setting the correct file path is the responsibility of the caller of f. If the filename comes from the command line parameters (sys.argv), then it is the responsibility of the person who runs the program to provide the correct path, like src/file.txt.

Tests complain about missing attribute assert_called, assert_called_once, ...

These require at least Python version 3.6. Check your installation. See the next question.

Problem when testing part01-e09

This is likely due to the tests using the numpy library and the library not being available to the test program.

See the next topic.

ModuleNotFoundError: No module named 'somelibrary'

The libraries needed in the course (numpy, pandas, matplotlib, scikit-learn, scipy, seaborn, and statsmodels) are contained in the Anaconda distribution. Either you haven't installed Anaconda or it hasn't been activated.

If you are using VSCode, the best way is to start VSCode from the anaconda navigator. If this does not work for you, try selecting a python interpreter that has the necessary libraries by accessing the "Python: Select interpreter" option from the Command palette (CTRL + SHIFT + P), and selecting a python 3.6 or higher with conda or anaconda in the path.

For non-Anaconda and/or non-VSCode users:

On Windows it may help, if you use 'Anaconda prompt' from the Windows menu. That should activate Anaconda automatically.

If you don't want to use 'Anaconda prompt', then in command prompt try where python to see if it finds Python under Anaconda's folder. If not, try to activate Anaconda with C:\Users\<username>\AppData\Local\Continuum\Anaconda3\Scripts\activate Or something similar, depending where you installed it.

On Linux/macOS:

You can check whether Anaconda is active with the command which python3. If the python3 binary is under anaconda3 folder, then Anaconda is active. If you are sure you have already installed Anaconda, then you can activate it with

  • conda activate, or

  • ~/acaconda3/bin/conda activate (or where ever Anaconda is installed)

  • On older Anaconda distributions use: source ~/anaconda3/bin/activate

Then try again which python3.

What version of Python should I use? What is the name of the executable?

The Python version should be at least 3.6. You can check your version with python3 --version on Linux or macOS, and with python --version on Windows. Note: on Linux the program python might refer to an old Python version 2. Don't ever use that!

Stuff generally doesn't seem to work in the conda prompt on Windows

Some environment variables apparently may not be properly set in the conda prompt directly after install. Try rebooting your system.

TMC test fails but all other commands (including submit) work

If you are using Windows and a fairly new installation of conda, you have fallen pray to a bug in conda. The python environment variables are not properly set for tmc to be able to run the tests. You can use python -m tmc in the project root instead. So in the folder where e.g. python src/hello_world.py works as expected the command python -m tmc should run tmc tests properly.

This workaround shouldn't be needed after the next version of conda is released.

When logging to tmc first time, whats the server address it asks?

Your TMC client is old, load newest version from tmc-cli

TMC login crashes (with mention of tmc-cli.log)

Your java version is probably too old. If you want, you can check the log file that should be located in <user.home>/.config/tmc-cli/logs. There should be mention of SSLHandshakeException or similar security related exceptions. In this case you should update to a newer version of java.

For java 8, at least open jdk 1.8.0_212 and 1.8.0.211 work. All java 11 and 12 version should work.

tmc not found

You installed the TMC client successfully, but the program is not found when you say tmc in the command prompt. If you are using Windows, use the doskey program so that tmc can be found even if you are not in the same folder as the tmc executable. For instructions, see tmc-cli <https://github.com/testmycode/tmc-cli>_.

If you are using Linux, then you may have close the terminal window and open a new one. Or alternatively, run source ~/.bashrc.

tmc test says: "Test results: 0/0 tests passed"

If the output is Test results: 0/0 tests passed All tests passed! Submit to server with 'tmc submit' Then several things can be wrong.

First make sure that the program run correctly, e.g. python3 src/hello_world.py. If it crashes, then tmc will most likely give the above message.

If the program does not crash, you are using Windows, and you have installed Anaconda, then possibly TMC cannot find Anaconda installation. Make sure you use TMC version at least 0.9.2. You can check the version of TMC with tmc --version. If it still does not work, then try to activate Anaconda. To achieve this check the question: ModuleNotFoundError: No module named ‘somelibrary’

I cannot understand the error message from a failed test case

First run tmc update to make sure the test hasn't already been patched. If the problem persists, make a bug report in:

Note that reporting that "tests should be better" doesn't really help. Please try to be more specific with bug reports. You can for example consider the following:

  • What was the error message?

  • What was the actual issue if you managed to fix it?

  • Link to non-working code

  • If reported via Discord: What was the exercise in question?