Poor Richard's Settings Framework

Defines a simple settings framework targeting values set via environment variables. PRSF is self contained and should be copy and pasted to other projects which need global application settings.

Features:

• Works with IDE auto-complete
• No external dependencies
• Automatically pull values from environment variables and set on your class
• Simple static class (no singletons)
• Typecast primitive types via hints (int, bool, str)
• Thread safe

Usage

Add fields as class variables to the Settings object. At the entry point of your app, inject the environment variables and validate there are no missing settings.

Environment variables are expected to have a prefix (e.g. your app name). The are parsed, prefix removed, lowercased and set as attributes on the class. For example if the prefix is MYAPP_ then MYAPP_MY_SETTING would correspond to Settings.my_setting.

from . import conf

conf.update_from_env(conf.Settings, "MYAPP_")
missing_settings = conf.get_missing_settings(conf.Settings)
if len(missing_settings) > 0:
    for s in missing_settings:
        logger.error(f"Undefined setting {s}")
    sys.exit(1)

print("All required settings are defined")

Upgrading

You'll have to manually make your changes if you copy/pasted into your application. Use git diff or Github to diff the version you're currently on with the target or latest version. The functions should be replaceable and changes to the Settings class minimal. PSRF uses semantic versioning so backward incompatible changes will be noted with a new major version number.