interpolate flag functionality is not implemented

[r4victor]

I did SECRET_KEY = env('DJANGO_SECRET_KEY') and got the error:

django.core.exceptions.ImproperlyConfigured: Set the a&d3*0k#skh)!5o)$))zz9&%hr@-akid5zh--05ei790+wn0$r environment variable

This is becuase my DJANGO_SECRET_KEY starts with the dollar sign:

DJANGO_SECRET_KEY="$a&d3*0k#skh)!5o)$))zz9&%hr@-akid5zh--05ei790+wn0$r"

There was a number of issues for this problem: #284, #60, #271.

Eventually, #333 somewhat solved the issue by allowing to escape the dollar sign. But this is not the best approach for generated values such as secret keys. The better option would be an ability to disable interpolation altogether. Ideally by default since the behaviour is unexpected.

Interestingly, the interpolation flag is described in the docs: https://django-environ.readthedocs.io/en/latest/tips.html?highlight=Proxied%20Values#proxy-value. BUT it's not implemented! This commit introduced the doc. Apparently, the implementation (#145) was not merged and closed in favor of #333. I don't know why. #145 seems like a proper solution.

[ebridges]

It does appear to work albeit in a limited fashion, e.g. here's the example from the docs, plus the use case I'm looking for (embedding db credentials into a db url). The example from the docs works but the URL case does not. Given that the word interpolate only occurs in the documentation in the code base, it seems that it's relying on some kind of implicit behavior.

import environ

TEST_ENV='test.env'

with open(TEST_ENV, 'w') as f:
    f.write('FOO=bar\n')
    f.write('BAR=$FOO\n')
    f.write('URL=abc://$FOO\n')

env = environ.Env(interpolate=True)
env.read_env(TEST_ENV)

bar = env('BAR')
url = env('URL')

print(f'bar: {bar}, url: {url}')

[r4victor]

@ebridges, interpolate=True seems to work because interpolation is a default behaviour. Try calling environ.Env() or environ.Env(interpolate=False) and you'll get the same result.

[ebridges]

Yes I agree. Because I needed this functionality I have simply switched to use python-dotenv which offers that.

[ThalusA]

This feature will really be never implemented ?

[daggaz]

This one just tripped me up too. Any chance the attached PR will be merged soon? In my case, I'm generating and setting a django secret key, and it ended up randomly starting with $, which caused me bit of confusion...

[sergeyklay]

This is implemented in #419. Thank you for the report.