Summary

Python on HPC

HPC centers have different quality of documentation: you are encouraged to file a support ticket to request better documentation.

To login to your HPC cluster via the terminal, one can use SSH as shown below, but the exact syntax differs per cluster:

ssh my_user_name@my_hpc_cluster.se

To find and load your favorite Python version one can use the commands below, but the exact syntax differs per cluster:

module spider python
module load python

Python is an interpreted language. This means that an interpreter reads my code, converts it to machine code and then runs that machine code.

The Python interpreter is started with:

python

The go-to text editor on an HPC cluster is called nano, with emacs and vim being more advanced text editors. nano can be started with:

nano

To create a Python script, one can do:

nano my_script.py

To run a Python script, one can do:

python my_script.py

Basic Python

How to Think Like a Computer Scientist: Learning with Python 3 is a fine book to start learning Python from.

To create a variable in Python, do:

my_variable = 3.14

To print a variable in Python, do:

print(my_variable)

To do exponentiation in Python, use **:

my_variable = 3 ** 2

To use the modulo operator, %, which is useful to determine if a number is odd/even/prime, in Python do:

my_variable = 5 % 2

To ask the user to give a number, use input:

t_now = int(input("Enter the current hour"))

To read a file, use open and readlines and close:

f = open("friends.txt", "r")
xs = f.readlines()
f.close()

To write to a file, use open and readlines and close:

g = open("sortedfriends.txt", "w")
for v in xs:
    g.write(v)
g.close()