classoptions 0.1

Implement namespaced and inheritable metadata at the class level.

classoptions

Description

Implement namespaced and inheritable metadata at the class level.

Inspired on Meta classes from Django and Django Rest Framework.

Quick Start

Installation

pip install classoptions

Simple inheritance

In the example, DefaultInfo holds metadata that is inherited by subclasses, while Info holds class specific metadata.

from classoptions import get_options_metaclass
EmployeesInfoMetaclass = get_options_metaclass("EmployeesInfoMetaclass", "Info", "DefaultInfo")

class Pizza(metaclass=EmployeesInfoMetaclass):
    class DefaultInfo:
        client_can_modify = True
        notes = None

    cooking_temp = 400
    cooking_time = 1    

class HawaiianPizza(Pizza):
    ingredients = ["cheese", "ham", "pineapple"]
    
    class Info:
        notes = "Do not judge the costumer."
        private_note = "If planning a party, ask first if people like it."
        
print("Hawaiian Pizza:")
print("Ingredients:", ", ".join(HawaiianPizza.ingredients))
print("Cooking Temperature (F):", HawaiianPizza.cooking_temp)
print("Cooking Time (hours):", HawaiianPizza.cooking_time)
print("Client can modify:", HawaiianPizza.Info.client_can_modify)
print("Notes:")
print(HawaiianPizza.Info.notes)
print("Private Note:")
print(HawaiianPizza.Info.private_note)

Output:

Hawaiian Pizza:
Ingredients: cheese, ham, pineapple
Cooking Temperature (F): 400
Cooking Time (hours): 1
Client can modify: True
Notes:
Do not judge the costumer.
Private Note:
If planning a party, ask first if people like it.

Multiple Inheritance

Works similar to python inheritance, except we don't need to explicitly inherit from the parent class.

from classoptions import get_options_metaclass
OptionsMetaclass = get_options_metaclass("OptionsMetaclass", "Options", "DefaultOptions")

class A(metaclass=OptionsMetaclass):
    class DefaultOptions:
        color = "red"
        size = 2
        hello = "world"
        i_like_pizza = True

class B(A):
    class DefaultOptions:
        color = "blue"
        size = 3

class C(B):
    class Options:
        size = 4  # Specific to C only

class D(A):
    class DefaultOptions:
        color = "black"
        hello = "country"

class E(D, C):
    class Options:
        i_like_hawaiian_pizza = "maybe"

print("E custom options")
print("i_like_hawaiian_pizza:", E.Options.i_like_hawaiian_pizza)

print("\nInherited from B")
print("size:", E.Options.size)

print("\nInherited from D")
print("color:", E.Options.color)
print("hello:", E.Options.hello)

print("\nInherited from A")
print("i_like_pizza:", E.Options.i_like_pizza)

Output:

E custom options
i_like_hawaiian_pizza: maybe

Inherited from B
size: 3

Inherited from D
color: black
hello: country

Inherited from A
i_like_pizza: True

License

MIT License.