> “Software entities … should be open for extension but closed for modification”
In other words: You should not need to modify the code you have already written to accommodate new functionality, but simply add what you now need.
Intention: Add a `Median` function
```python
import numpy as np
from abc import ABC, abstractmethod
class Operations(ABC):
'''Operations'''
@abstractmethod
def operation():
pass
class Mean(Operations):
'''Compute Max'''
def operation(list_):
print(f"The mean is {np.mean(list_)}")
class Max(Operations):
'''Compute Max'''
def operation(list_):
print(f"The max is {np.max(list_)}")
class Main:
'''Main'''
@abstractmethod
def get_operations(list_):
# __subclasses__ will found all classes inheriting from Operations
for operation in Operations.__subclasses__():
operation.operation(list_)
if __name__ == "__main__":
Main.get_operations([1,2,3,4,5])
# The mean is 3.0
# The max is 5
```
---
- Reference:
- [[( 2021-11-10 Solid Coding in Python]]
- Related:
- [[abstract-base-classes]]