ridiculously small config loader. i'm not joking. this is tiny!

miniconf.py

import inspect
import os
import yaml
from pathlib import Path

CONFIG = None


class MiniConf:
    def __init__(self, **kwargs):
        self._cfg_file = Path(kwargs.get("cfg_file", "."))
        self._name = self._cfg_file.name.replace(self._cfg_file.suffix, "")
        self._load_config()
        self._pull_envars()

    def _load_config(self):
        with self._cfg_file.open("r+") as cfg:
            try:
                cfg_dict = yaml.load(cfg, Loader=yaml.FullLoader)
            except:
                return
        for sub_import in cfg_dict.pop("_import", []):
            new_conf = MiniConf.from_path(sub_import)
            if isinstance(new_conf, list):
                for conf in new_conf:
                    setattr(self, conf._name, conf)
            elif isinstance(new_conf, MiniConf):
                setattr(self, new_conf._name, new_conf)
        self.__dict__.update(cfg_dict)

    def _pull_envars(self):
        if getattr(self, "_envar_prefix", ""):
            for key, val in os.environ.items():
                if key.startswith(self._envar_prefix):
                    self.__dict__[key] = val

    @classmethod
    def from_path(cls, conf_path):
        conf_path = Path(conf_path)
        if not conf_path.exists():
            return
        if conf_path.is_dir():
            return [MiniConf.from_path(p) for p in conf_path.glob("*.mconf") if p]
        if conf_path.suffix == ".mconf":
            return MiniConf(cfg_file=conf_path)


if not __name__ == "__main__":
    for frame in inspect.stack():
        filename = getattr(frame, "filename", "")
        if ".py" in filename and "miniconf.py" not in filename:
            CONFIG = MiniConf.from_path(Path(filename).parent)
            if isinstance(CONFIG, list):
                CONFIG = [
                    conf
                    for conf in CONFIG
                    if not any(getattr(c, conf._name, False) for c in CONFIG)
                ]
                CONFIG = CONFIG[0] if len(CONFIG) == 1 else CONFIG
            break

.mconf files are just yaml with two extra features (_import and _envar_prefix)

_import:
    - another.mconf
    - conf
    - sub/whatever.mconf
_envar_prefix: "PROJECT_"
key: "value"
a: 5
things:
    - 1
    - 2
    - 3

To use it, simply do

from miniconf import CONFIG