magnet 1.1.1

Hierarchical YAML config reader that reads from multiple files and an environment variable

magnet

A library that makes it easy to load YAML config files in a hierarchical manner. Also loads YAML content from CONFIG environment variable.

Minimal Python version is Python 3.5.

Installation

pip install magnet

Usage

Consider the following yaml file config/default.yml:

app:
  url: https://www.example.com/app
  certs:
    pem: /path/to/cert.pem
    key: /path/to/cert.key
  clients:
    - a
    - b

And the following config/local.yml file:

app:
  url: https://app.example.com/

from magnet import Config

config = Config().read_all()

config['app.url']           # ==> "https://app.example.com"
config['app.certs.pem']     # ==> "/path/to/cert.pem"
config['non.existing.key']  # ==> raises KeyError

Additional options:

from magnet import Config

# Listed below are the default parameters 
config = Config(
    config={
        # set default configuration here
    },
    filenames=(
       'config/default.yml',
       'config/local.yml',
    ),
    env_variable='CONFIG',
    separator='.',
)

config.read_all(
  filename=None,  # string, can be set to load an additional file
)

This will load the configuration in the following order:

1. ./config/default.yml - can be committed to the repository
2. ./config/local.yml - should not be committed to allow custom config for devs
3. An additional YAML config file (if filename argument is defined)
4. YAML contents from the CONFIG environment variable (if env_variable is defined)

All of these files are optional, but the key lookups will result with KeyError if a key is missing. If filename is defined, but the file is not found, it will raise a FileNotFoundError.

Development

make ci            - Run the CI pipeline (deps, lint, test-coverage)
make lint          - Lint all project files
make test          - Run all tests
make test-watch    - Run all tests and re-run on file changes
make test-coverage - Run all tests and calculate test coverage
make deps          - Create a virtual environment and install dependencies
make freeze        - Freeze the requirements
make env           - Create a virtual environment