Using the Python interpreter¶

Learning objectives

Practice using the UPPMAX documentation
Practice using the Python book How to Think Like a Computer Scientist: Learning with Python 3
To be able to login to Rackham autonomously
To be able to load a Python version autonomously
to be able to start an interactive session autonomously
To be able to run a minimal Python program autonomously

For teachers

Teaching goals are:

Learners have used the UPPMAX documentation
Learners have used the Python interpreter
Learners have loaded Python using the module system

Other goals are:

Verify that learners indeed have learned how to login
Verify that learners indeed have learned how to start an interactive session
Verify that learners indeed have learned how to use the module system

Prior question:

What is Python?
What are features of the Python language?
What is an interpreted language?
What is a scripting language?
What is an interpreter?
What is an HPC cluster?
What are features of the Rackham HPC cluster?
What is the rule on what to run on a login node?
When to use an interactive session?

Lesson plan:

5 mins: prior knowledge
5 mins: presentation
15 mins: challenge
5 mins: feedback

Why?¶

You want to make a computer run Python code, for some good reason. Here we do so!

To develop code in Python on the UPPMAX clusters, one needs to:

Login to Rackham, to be on an UPPMAX cluster
Load the Python module, to be able to use a modern Python interpreter
Use the Python interpreter, to run Python code

Luckily, UPPMAX has documentation that should allow you to do so yourself!

These exercises will ensure you are able to run a minimal Python program.

flowchart TD
    python[[Python]]

    %% Give a white background to all nodes, instead of a transparent one
    classDef node fill:#fff,color:#000,stroke:#000

    subgraph sub_programming_language[Python as a language]
      interpreted_language[Interpreted language]
      programming_language[Programming language]
      scripting_language[Scripting language]
      interpreter[Interpreter]
      %% scripts[Scripts]
      %% text_files[Text files]
    end
    style sub_programming_language fill:#ccf,color:#000,stroke:#fcc


    subgraph sub_uppmax[UPPMAX]
      uppmax[UPPMAX]
      uppmax_modules[UPPMAX modules]
      uppmax_clusters[UPPMAX clusters]
      %% text_editors[Text editors]
      %%x_forwarding[X-forwarding]
      %%remote_desktop[Remote desktop]
    end
    style sub_uppmax fill:#fcc,color:#000,stroke:#fcc

    python --> |is a| programming_language
    python --> |is a| interpreted_language
    python --> |is a| scripting_language

    %% programming_language --> |uses| text_files
    interpreted_language --> |has a| interpreter
    scripting_language --> |is a|interpreted_language
    %% scripting_language --> |runs| scripts
    %% scripts --> |are| text_files
    %% scripts --> |can use| command_line_arguments

    uppmax --> |has| uppmax_clusters
    uppmax_clusters --> |have| uppmax_modules
    %%uppmax_clusters --> |have| text_editors
    %%uppmax_clusters --> |allow| x_forwarding
    %%uppmax_clusters --> |has| remote_desktop
    %% uppmax_modules --> |allow the use of| python_packages
    uppmax_modules --> |allow the use of| interpreter

    %% text_editors --> |work on|text_files
    %%x_forwarding --> |allows|graphics
    %%remote_desktop --> |allows|graphics


    %% variables ~~~ uppmax

Exercises¶

Enjoy a video?

You can find a video with solutions to these exercises here

See the exercise procedure here.

Go to the UPPMAX documentation at https://docs.uppmax.uu.se, then answer these questions:

Login to Rackham in any way

Answer

This is described at the UPPMAX page 'Login to Rackham':

Remote desktop via website: go to https://rackham-gui.uppmax.uu.se
Using SSH:

ssh -X sven@rackham.uppmax.uu.se

Exercise 2: start an interactive session¶

Learning objectives

to be able to start an interactive session autonomously

Go to the UPPMAX documentation at https://docs.uppmax.uu.se, then answer these questions:

Start an interactive session of max seven hours

If this does not work out, go to the next step: we will be only doing light work on the login node. However, using an interactive session is a good idea.

Answer

This is described at the UPPMAX page 'Starting an interactive node on Rackham':

interactive -A naiss2024-22-49 -t 7:00:00

Exercise 3: load the Python module¶

Learning objectives

to be able to load a Python version autonomously

Go to the UPPMAX documentation at https://docs.uppmax.uu.se, then answer these questions:

Load Python version 3.10.8

Answer

This is described at the UPPMAX pages on Python:

module load python/3.10.8

Exercise 4: write a 'Hello world' program¶

Learning objectives

to be able to run a minimal Python program autonomously

Go to the UPPMAX documentation at https://docs.uppmax.uu.se, then answer these questions:

Start Python on Rackham

Answer

Type

python

to start the Python interpreter

Find the UPPMAX documentation page on Python programming

Answer

It can be found at https://docs.uppmax.uu.se/software/python_programming/

On the UPPMAX documentation page on Python programming, find out how to run a 'Hello world' program from the interpreter. Then do this yourself

Answer

The documentation can be found at https://docs.uppmax.uu.se/software/python_programming/#use-the-python-interpreter.

In the Python interpreter, type

print('Hello, world!')

to run your 'Hello world' program

Using the Python interpreter¶

Why?¶

Exercises¶

Exercise 1: login to Rackham¶

Exercise 2: start an interactive session¶

Exercise 3: load the Python module¶

Exercise 4: write a 'Hello world' program¶