confpy

Confpy is an open-source Python library that provides a unified interface for application configuration. It is designed to let applications read configuration from multiple sources—environment variables, configuration files, and command-line arguments—in a predictable and testable way. The project emphasizes simple semantics, deterministic merging, and validation.

At its core, confpy uses a hierarchical configuration model. Keys are organized in a nested dictionary-like structure, and the library merges sources according to a configurable precedence: defaults, files, environment variables, and runtime overrides. It supports watching files for changes and optional hot-reloading in long-running processes.

Confpy accepts configuration from several formats, commonly YAML, JSON, and INI, via adapters. It can also read plain Python dictionaries. For correctness, it provides schema-based validation and type coercion, allowing developers to declare required fields and allowed value types. It also supports environment-variable prefixing and automatic type conversion (for example, turning a string 'true' into a boolean).

Usage patterns include loading a base configuration file, layering environment-specific overrides, and exposing a read-only view to application code. The library aims to be lightweight with a minimal API surface for easy testing.

Development and community: Confpy is maintained by an open-source community and is hosted on public repositories with issue trackers and contributor guidelines. It emphasizes stability, backward compatibility, and clear documentation. Related projects in the ecosystem include general Python configuration tooling and schema-based validation libraries.

See also: Python configuration management; YAML; JSON; TOML; INI; Environment variables.