- __dir__ is called when the built-in dir function is called on the module
- __getattr__ is called when an attribute is not found via the regular attribute lookup
Let's use this to build an environment based configuration module.
- Conviruation values has a value, environment key and a function to convert from str to right type
- I'm going to use dataclasses and populate values from environment in __post_init__
- Complex data types (such as list) should be JSON encoded in the environment variables
- All configuration values with start with the c_ prefix
- __dir__ will return a list configuration variables without the c_ prefix
- __getattr__ will add the c_ prefix and will look for the varialbes in globals
We're adding c_ prefix and removing it to bypass the regular attribute lookup mechanism. If we'll call a variable http_port and user will write config.http_port, our __dir__ function won't be called.
Here's the code
