Config With YAML

Config With YAML is a pure-Python package to load config YAML files.

Installation

pip install config_with_yaml

Quick Start

from config_with_yaml import Loader

loader = Loader()
cfg = loader.load("config.yml")

print(cfg.getProperty("database.host"))
print(cfg.getPropertyWithDefault("database.port", 5432))
print(cfg)

Using !include

The Loader class supports the !include tag to include external YAML files. Paths are resolved relative to the current file's directory.

# config.yml
app_name: myapp

database: !include database.yml
features: !include features.yml

# database.yml
host: localhost
port: 5432

# features.yml
debug: true
max_connections: 100

Loading the config:

from config_with_yaml import Loader

loader = Loader()
cfg = loader.load("config.yml")

print(cfg.getProperty("app_name"))       # myapp
print(cfg.getProperty("database.host"))  # localhost
print(cfg.getProperty("features.debug")) # true

Chained Includes

Includes can be chained (A includes B includes C). By default, maximum depth is 5.

# level1.yml
data: !include level2.yml

# level2.yml
nested: !include level3.yml

# level3.yml
value: deep_value

cfg = loader.load("level1.yml")
print(cfg.getProperty("data.nested.value"))  # deep_value

Relative Paths

Use relative paths to include files from other directories:

# subdir/config.yml
data: !include ../shared/common.yml

Configuration

The Loader class accepts the following parameters:

• max_include_depth (int): Maximum depth for nested includes (default: 5)
• log_level (int): Logging level (default: logging.DEBUG)
• config_paths (str): Additional colon-separated paths to search for config files

import logging
from config_with_yaml import Loader

loader = Loader(
    max_include_depth=3,
    log_level=logging.INFO,
    config_paths="/path/to/configs:/another/path"
)

cfg = loader.load("config.yml")

Environment Variables

• YAML_CONFIG_PATHS: Colon-separated paths to search for config files (in addition to current directory)

export YAML_CONFIG_PATHS=path/to/folder1:path/to/folder2

Legacy API (Deprecated)

The old load() function is still available but deprecated:

import warnings
from config_with_yaml import load

# This will show a DeprecationWarning
warnings.filterwarnings('ignore', category=DeprecationWarning)
cfg = load("config.yml")

Migration: Replace with:

from config_with_yaml import Loader

loader = Loader()
cfg = loader.load("config.yml")

Config File Format

Example YAML config:

Demo:
  Motors:
    Server: ROS
    Proxy: Motors:default -h localhost -p 9001
    Topic: '/turtlebotROS/mobile_base/commands/velocity'
    Name: basic_component_pyCamera
    maxW: 0.7
    maxV: 4

  Camera:
    Server: ROS
    Proxy: "CameraL:default -h localhost -p 9001"
    Format: RGB8
    Topic: "/TurtlebotROS/cameraL/image_raw"
    Name: basic_component_pyCamera

  NodeName: demo

Access properties:

cfg = loader.load("demo.yml")
print(cfg.getProperty("Demo.Motors.Server"))       # ROS
print(cfg.getPropertyWithDefault("Demo.Motors.X", "default"))  # default
print(cfg.getProperty("Demo.Camera.Format"))        # RGB8

Testing

pip install -e ".[dev]"
pytest tests/