Default variables with python-dotenv

Question

I want to make a package that works out of the box with reasonable default variables, like defining some servers, ports etc. so that the code works for an average user like he expects it without further configuration. But I want this environment variables to be overriden if a .env file exists in order to allow configuration for other environments. I read that python-dotenv load_values will use defaults if no .env file exists, but there is no example on pypi how that would set up ideally.

Did you see the example involving the construction of a dict using `dotenv_values` and `os.environ`? — chepner, Jan 20 '23 at 18:16
@chepner I tried to answer it myself with your hint. Maybe you can have a look. — FordPrefect, Jan 20 '23 at 19:07
That's exactly right. It's not for `dotenv` to provide defaults, but for the application to *use* `dotenv` to override defaults. — chepner, Jan 20 '23 at 19:09

score 1 · Answer 1 · answered Jan 20 '23 at 18:16

1

i think this way would work.

default_dict = {'API_KEY':'test'} #e.x for an api_key 

try:
    load_dotenv(find_dotenv())
    api_key = os.getenv("API_KEY")
except:
    api_key = default_dict['API_KEY']

answered Jan 20 '23 at 18:16

Amin S

546
1
14

That would be an idea, thx. – FordPrefect Jan 20 '23 at 18:42
Don't use a bare `except`: at least use `except Exception`, if not an even more specific exception class for what you expect could be raised. – chepner Jan 20 '23 at 18:45

FordPrefect · Accepted Answer · 2023-01-20T19:38:53.593

1

Reading the comment of @chepner I think there might be a solution using merge. Didn't know about that feature yet.

from dotenv import dotenv_values


default_envs = {"MY_SERVER": "https://my-server.com"}
config = {
    **default_envs,
    **dotenv_values
}

This might be nice, because it allows for partial override and I don't need to go through all variables.

Comments are welcome.

edited Jan 20 '23 at 19:38

answered Jan 20 '23 at 19:01

FordPrefect

320
2
11

Default variables with python-dotenv

2 Answers2