Application Properties

0.9.2 · active · verified Sat Apr 11

Application-properties is a Python library (current version 0.9.2) that provides a simple, unified manner of accessing program properties. It supports loading configuration from various formats including JSON, TOML, YAML, JSON5, and traditional .properties files. The library emphasizes ease of use, testability, extensibility, and hierarchical property access, releasing frequently with new features and fixes.

Warnings

gotcha Starting from version 0.9.2, the library's loaders for JSON, YAML, and TOML gained enhanced support for handling `.` characters within keys. By default, `.` implies hierarchical structure. If you relied on `.` being treated as a literal character in keys for these formats in older versions, you might need to adjust your configuration or use the 'master switch' to control this behavior.
Fix: Review configuration files (especially JSON, YAML, TOML) to ensure correct hierarchical parsing. If a literal `.` in a key is intended, consult the official documentation for the 'master switch' to disable hierarchical interpretation for specific keys or loaders.
gotcha Functionality for YAML, TOML, and JSON5 files requires installing optional dependencies. If these are not installed, attempts to load these file types will fail with import errors.
Fix: Install with optional extras, e.g., `pip install application-properties[yaml,toml,json5]` to include all supported loaders. Install only the specific extras you need to avoid unnecessary dependencies.
breaking The `application-properties` library requires Python 3.10 or newer. Installing or running on older Python versions will result in environment or syntax errors.
Fix: Ensure your Python environment is version 3.10.0 or higher. Upgrade Python if necessary.

Install

pip install application-properties Base installation
pip install application-properties[yaml,toml,json5] With all optional loaders

Imports

ApplicationProperties

from application_properties import ApplicationProperties

Quickstart

Demonstrates how to load properties from a simple `.properties` file and access values. The example creates a temporary `config.properties` file and cleans it up afterwards.

import os
from application_properties import ApplicationProperties

# Create a dummy config file for demonstration
config_content = """
my.setting = some_value
another.setting = 123
"""
with open("config.properties", "w") as f:
    f.write(config_content)

try:
    # Load properties from a file named config.properties
    app_props = ApplicationProperties("config.properties")

    # Access a property
    value = app_props.get_string_property("my.setting")
    print(f"Value of 'my.setting': {value}")

    # Access a property with a default value if not found
    not_found_value = app_props.get_string_property("non.existent", "default_value")
    print(f"Value of 'non.existent' (with default): {not_found_value}")

except Exception as e:
    print(f"An error occurred: {e}")
finally:
    # Clean up the dummy file
    if os.path.exists("config.properties"):
        os.remove("config.properties")

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