yaconfiglib 0.10.0

Another Config lib for python, basically load config/yaml/toml/... files and add some features like relative import and templating.

yaconfiglib

yaconfiglib is a modern, extensible configuration parser library for Python. It allows you to seamlessly load, merge, and interpolate multiple configurations in a variety of formats (YAML, TOML, JSON, INI, .env), or execute scripts/commands directly to retrieve configuration objects dynamically.

Zero required runtime dependencies (except standard pathlib, with optional packages to enable extra backends).

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Features

• Standard Library API Parity: Drop-in replacements for standard serialization modules using yaconfiglib.load(), loads(), dump(), and dumps().
• Backend Registry & Plugins: Core loaders for TOML, YAML, JSON, INI, and .env. Easily extend the library by registering custom configuration loader classes.
• Model Validation (load_as): Automatic hydration and verification of Pydantic models or standard Python dataclasses directly from loaded configuration files.
• Dot-Notation Access: Configuration results are wrapped in a DotAccessibleDict supporting deep traversal like config.database.credentials.user and toggleable dig options.
• Shell & Command Execution: Execute arbitrary commands or shell scripts dynamically (e.g. cmd://aws... or ./generate.sh) and auto-parse their outputs, with support for shebang-based format routing (e.g. #!json header).
• YAML Includes: Out-of-the-box support for !include and !load YAML constructors to seamlessly and recursively import child configurations or commands.
• Advanced Templating: Interleave configurations with Jinja2. Generate configuration blocks dynamically, auto-inject os.environ via env.VAR_NAME, or reference previously declared values using Jinja's {% do %} statements.
• Environment Overlays: Load prefixed environment variables as flat or nested configuration, with optional scalar coercion for booleans, numbers, nulls, arrays, and objects.
• Path Agnostic: Compatible with both standard pathlib.Path and optionally pathlib_next for URI loading (HTTP, SFTP, etc.) exactly like standard file paths.

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Installation

Install using pip:

pip install yaconfiglib

Optional dependencies:

Extra	Adds	Needed for
yaconfiglib[yaml]	pyyaml	Parsing YAML configuration files and !include tags
yaconfiglib[toml]	toml	Parsing TOML configuration files
yaconfiglib[jinja2]	jinja2	Jinja2 templating, environment variables injection, and transformations

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Quick Start

1. Simple Parsing and Dot-Notation Access

import yaconfiglib

# Load a YAML file
config = yaconfiglib.load("config.yaml", interpolate=True)

# Traverse configuration like attributes
print(f"Server starting on: {config.server.host}:{config.server.port}")

2. Hydrate Model (Pydantic / Dataclasses)

from pydantic import BaseModel
import yaconfiglib

class DBConfig(BaseModel):
    host: str
    port: int

# Hydrate the Pydantic model directly
db_settings = yaconfiglib.load_as(DBConfig, "config.yaml", loader="yaml")
print(db_settings.host)

3. Dynamic Includes & Shell Commands

In your config.yaml:

# Recursively include other files
database: !include "db_settings.toml"

# Dynamically execute commands to retrieve parameters (e.g. secrets)
secrets: !include 'cmd+json://python -c "import json; print(json.dumps({\"token\": \"super-secret\"}))"'

4. Environment Variable Overlays

from yaconfiglib import ConfigLoader
from yaconfiglib.backends.env import EnvVarBackend

# APP_DB__PORT=5432 -> {"db": {"port": 5432}}
config = ConfigLoader().load(
    loader=EnvVarBackend(prefix="APP_", nested_delimiter="__", coerce=True)
)

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API Overview

Module	Purpose
yaconfiglib.loader	Core ConfigLoader orchestrator, load(), loads(), dumps(), and DotAccessibleDict
yaconfiglib.backends	ConfigBackend protocol & registry
yaconfiglib.backends.yaml	YamlConfig parsing and include tag construction
yaconfiglib.backends.toml	TomlConfig parsing (using stdlib tomllib or toml package fallback)
yaconfiglib.backends.json	JsonConfig parsing
yaconfiglib.backends.ini	IniConfig parsing
yaconfiglib.backends.dotenv	DotenvBackend for parsing .env files
yaconfiglib.backends.env	EnvVarBackend for loading os.environ variables with prefix matching
yaconfiglib.backends.command	CommandBackend for running processes and auto-routing outputs
yaconfiglib.backends.python_backend	PythonBackend for in-memory python dict injection
yaconfiglib.utils.merge	Deep dict/list merge algorithms and custom merge methods
yaconfiglib.utils.jinja2	Custom Jinja2 interpolation environments and render utilities

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Development

pip install -e ".[dev]"
pytest -q

Releasing

This project follows Semantic Versioning and keeps a CHANGELOG.md. Pushing a tag matching v* triggers the release workflow: test gate → build → publish → docs deploy.

Documentation site

MkDocs builds the API reference from docs/, published on every release. To preview locally:

.venv/Scripts/pip install -e ".[docs]"
.venv/Scripts/mkdocs serve

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License

MIT — see LICENSE.