py-app-properties 1.2.0

Java application properties for Python

Python Application Properties

What is this

This is a simple library to inject non-sensitive configurations into class variables.

How to install

To install this library just enter:

pip install py-app-properties

How To Use

The main purpose of this library is to simplify work with an application config. Using decorator @properties with all required params and type hinting you can inject required settings from *.yml or *.json formats.

Example:

# my_app_properties.yml
my_class:
  int_var: 10
  list_int_var:
    - 12
    - 14
  dict_with_list_var:
    key1:
      - val1
      - val2
    key2:
      - val3
      - val4
  bool_var: true

from app_properties import properties

@properties(filename="my_app_properties.yml", root="my_class")
class MyClass:
    int_var: int
    list_int_var: list[int]
    dict_with_list_var: dict[str, list[str]]
    bool_var: bool
    
    def __init__(self, param1: int, param2: str) -> None:
        self._param1 = param1
        self._param2 = param2
    
    def some_method(self) -> None:
        ...  # using class variables and instance variables here

About params:

• filename - the name of a file with config. By default, it is application.yml which is located in the same directory as a file with a used decorator. Use a relative path with ../ to read the file from a parent directory.
• type_cast - used to know whether you want to cast config values to field type. By default, it's True, which means values in a config file will be cast according to the type hints. If False, type hinting is ignored, and available types are limited by a file format - only list, dict, int, str, float, bool, and none are available. If True - set, frozenset, tuple, NamedTuple, TypedDict, and dataclass will be available additionally to types above. Also nested types will be recursively cast.
• override_default - used to know whether you want to override default values of class variables. By default, it is False.
• root - root key in the config. Could be a nested value with separation by dots, for example:

# example.yml
some:
  nested:
    config:
      key: value

@properties(filename="example.yml", root="some.nested.config")
class MyClass:
    key: str

About contributing

You will make this library better if you open issues or create pull requests with improvements.