Appropriate Python Exception Class for Missing Settings File

Question

What is the appropriate python Exception to raise if there is a missing settings file?

For example, in Django projects, a light-weight way to allow users to define local settings is to add the following snippet to the settings.py file

try:
    from local_settings import *
except ImportError:
    # want to add informative Exception here
    pass

thus, any local settings override the defaults in settings.py.

Answer 1

The usual exception for missing files is IOError.

You can customize the wording by creating a subclass:

class MissingSettingsFile(IOError):
    'Missing local settings file'
    pass

Then, use that custom exception in your code snippet:

try:
    from local_settings import *
except ImportError:
    raise MissingSettingsFile