## Description
Implement namespaced and inheritable metadata at the class level.
Inspired on Meta classes from Django models and Django Rest Framework model serializers.
## Quick Start
### Installation
`pip install classoptions`
### Simple inheritance
```python
from classoptions import ClassOptionsMetaclass
from typing import Any
class Pizza(metaclass=ClassOptionsMetaclass):
_meta: Any
class DefaultMeta:
client_can_modify = True
notes = None
cooking_temp = 400
cooking_time = 1
class HawaiianPizza(Pizza):
ingredients = ["cheese", "ham", "pineapple"]
class Meta:
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._meta.client_can_modify)
print("Notes:")
print(HawaiianPizza._meta.notes)
print("Private Note:")
print(HawaiianPizza._meta.private_note)
```
Outputs:
```text
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.
```python
from classoptions import ClassOptionsMetaclass
from typing import Any
class A(metaclass=ClassOptionsMetaclass):
_meta: Any
class DefaultMeta:
color = "red"
size = 2
hello = "world"
i_like_pizza = True
class B(A):
class DefaultMeta:
color = "blue"
size = 3
class C(B):
class Meta:
size = 4 # Specific to C only
class D(A):
class DefaultMeta:
color = "black"
hello = "country"
class E(D, C):
class Meta:
i_like_hawaiian_pizza = "maybe"
print("E custom meta")
print("i_like_hawaiian_pizza:", E._meta.i_like_hawaiian_pizza)
print("\nInherited from B")
print("size:", E._meta.size)
print("\nInherited from D")
print("color:", E._meta.color)
print("hello:", E._meta.hello)
print("\nInherited from A")
print("i_like_pizza:", E._meta.i_like_pizza)
```
Outputs:
```text
E custom meta
i_like_hawaiian_pizza: maybe
Inherited from B
size: 3
Inherited from D
color: black
hello: country
Inherited from A
i_like_pizza: True
```
### Using other class/attribute names
With ``ClassOptionsMetaclass.factory`` you can overwrite how you define default metadata, class specific metadata,
and how you access the result.
```python
from classoptions import ClassOptionsMetaclass
from typing import Any
class A(metaclass=ClassOptionsMetaclass.factory("Options", "DefaultOptions", "_options")):
_options: Any
class DefaultOptions:
color = "red"
size = 2
cooking_temp = 400
cooking_time = 1
class B(A):
class Options:
color = "blue"
print("B color:", B._options.color)
print("B size:", B._options.size)
```
Outputs:
```text
B color: blue
B size: 2
```
## License
MIT License.
