Python: Dynamically import module contents

Question

I have lots of

from myproject.settings import param1
from myproject.settings import ...

scattered all over my project.

Upon startup, I would like to load different "settings" module according to env var (for example export SETTINGS=myproject.settings2)

I tried to put in the myproject.__init__.py someting like

module_name = os.environ['SETTINGS']
m=__import__(module_name)
settings = m

but it won't work.

from myproject.settings import *
ImportError: No module named settings

How can this be achieved ?

Answer 1

Try using a bogus 'fromlist' argument.

mymodule = __import__(mod, fromlist=['a'])

It's worked for me before in situations similar to yours.

Answer 2

settings = __import__(os.environ['SETTINGS'])

but it won't work.

Why? Your approach is the right one. As example, Django does this the same way.

• GabiMe: I don't know I do from myproject.settings import * and get ImportError: No module named settings
• leoluk: __import__ imports the module, just access it by the variable you assigned it to; settings.SOME_SETTING = True

Answer 3

You could try to add the absolute path of myproject.settings to PYTHONPATH like so:

PYTHONPATH=$PYTHONPATH:$HOME/myproject/settings/ export PYTHONPATH

Now you could keep this in ~/.bashrc (assuming UNIX env). This way whenever you open a new terminal this path is added to PYTHONPATH. i.e. python interpretor would add this path to it's like of paths to look for while importing a module.

Now whichever path you are simply type import settings & since myproject/settings is present python would load settings file.

Hope this helps...

Answer 4

I tried the code below and it worked.

Here is my folder structure:

src/
 app.py
 settings/
 __init__.py
 production.py
 sandbox.py

In settings.__init__.py, I wrote:

import os 
settings_module = os.environ.get('APP_SETTINGS')
if not settings_module:
 from .sandbox import *
else:
 exec('from {} import *'.format(settings_module))

If the var env was not set, imports the sandbox module. If was setting, imports the module dynamically.

Hope this helps