Mahimman Bubugan Bud/Rufe (Open/Closed Principle, OCP) ya cewa mahadi na software su yi bud ga gama dadi amma rufe ga canji: ya kamata ka sabu halin aiki da sabuwa code, ba ta hanya ta gyara code da aka taida a jarida.
():
shape.kind == : * shape.r **
shape.kind == : shape.s **
shape.kind == : shape.w * shape.h
Kowane sabuwa nau'i ya tilasta canji ga jere na if/elif - rashin aminci da abin yatsa ga kulle.
from abc import ABC, abstractmethod
class Shape(ABC):
@abstractmethod
def area(self): ...
class Circle(Shape):
def __init__(self, r): self.r = r
def area(self): return 3.14159 * self.r ** 2
class Triangle(Shape): # NEW behavior = NEW class
def __init__(self, b, h): self.b, self.h = b, h
def area(self): return 0.5 * self.b * self.h
def total_area(shapes): # never changes again
return sum(s.area() for s in shapes)
Sabuwar Triangle bai bukaci sifofi na gyara ga total_area ba - faɗaɗa ba tare da sauya ba.
→ polymorphism / inheritance → strategy pattern (inject behavior)
→ plugins / interfaces → higher-order functions / callbacks
OCP wanda aka yi ta yada-yada ya zama waje-asali - tsammani da aka gina don sayi da ba zai zo ba. Ka yi amfani da shi inda sauya ya zama yiwuwa ("dokar ukuku": abstract bayan sayi ya bayyana jiya).
Gyara code da aka jarida sosai don sabu fasali yana da haƴar ƴauwa a kome code tun ya yi; OCP ya kaɗe saubuwa jiyya zuwa sabuwa, kufewar abubuwa.
She shine mahimmin ka bayan frameworks masu budewa da tsarin plugin — kuma ya dogara ga LSP, tunda subtypes masu canji ne ke kera "rufe" tsakiya aminci don barin ba tare da bauta ba.