Trouble understanding Bash and translating to Python

Question

I am trying to translate this from Bash to Python:

export file="${directory}/scrutation_$(date "+%Y%m%d_%H%M%S").log"

I know that export sets an environment variable, and that (date "+%Y%m%d_%H%M%S") is strftime("%d/%m/%Y, %H:%M:%S") in Python.

This is what I have tried:

import os
os.environ[file]= f"{directory}/scrutation[strftime("%d/%m/%Y, %H:%M:%S")].log"

Is this correct?

I don't know if it's intentional, but the f-string is invalid, the outer `""` should be changed to `''` — Cow, Jan 02 '23 at 13:05
See https://stackoverflow.com/questions/5971312/how-to-set-environment-variables-in-python. — ykerus, Jan 02 '23 at 13:06
Like so? `f'{directory}/scrutation[strftime("%d/%m/%Y, %H:%M:%S")].log' — answer007, Jan 02 '23 at 13:07

choroba · Accepted Answer · 2023-01-02T13:26:38.777

The name of the environment variable is a string, it needs to be quoted.

Double quotes aren't nested in f"", use single quotes for one of the pairs.

$(...) is the Command Substitution, i.e. you need to run the strftime, not include it in square brackets.

Also, you can use the same format string without changes, unless you really want to change the timestamp format.

os.environ['file'] = f'{directory}/scrutation_' \
    f'{datetime.now().strftime("%Y%m%d_%H%M%S")}.log'

1 Answers1