confiddler

Schema-checked YAML config files, with default values for missing fields.

The Basic Idea

1. Define your config file structure with a JSON schema.

2. Help your users get started by showing them a auto-commented default config which is:

   • auto-generated from your defaults, and
   • auto-commented with your schema description.

3. Load a user's config file with load_config(), which will:

   • validate it against your schema
   • auto-inject default values for any settings the user omitted

Install

Install from PyPI:

pip install confiddler

...or with conda:

conda install -c stuarteberg -c conda-forge confiddler

Quickstart

Define your schema

>>> from confiddler import dump_default_config, load_config

>>> schema = {
      "description": "Settings for a robot vacuum cleaner",
      "properties": {
        "speed": {
          "description": "Speed of the robot (1-10)",
          "type": "number",
          "minValue": 1,
          "maxValue": 10,
          "default": 1
        },
        "movement": {
          "description": "Movement strategy: random, raster, or spiral",
          "type": "string",
          "enum": ["random", "raster", "spiral"],
          "default": "random"
        }
      }
    }

Show your user the default config.

>>> dump_default_config(schema, sys.stdout, 'yaml')
speed: 1
movement: random

>>> dump_default_config(schema, sys.stdout, 'yaml-with-comments')
#
# Settings for a robot vacuum cleaner
#

# Speed of the robot (1-10)
speed: 1

# Movement strategy: random, raster, or spiral
movement: random

Load your user's config.

# my-robot-config.yaml

speed: 2

# (Other settings omitted -- will be set as default.)

>>> load_config('my-robot-config.yaml', schema, inject_defaults=True)
{'speed': 2, 'movement': 'random'}