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[英]Return a list of classes created dynamically that are named the same as the names passed in in Python
[英]Dynamically created classes with the same name
我正在嘗試使用以下類型在 Python 中動態創建子類:
class A:
@classmethod
def create_subclass(cls, name, attrs):
return type(name, (cls,), attrs)
for i in range(5):
x = A.create_subclass("B", {"func": abs})
print(A.__subclasses__())
這是我在 output 中看到的:
[<class '__main__.B'>, <class '__main__.B'>, <class '__main__.B'>, <class '__main__.B'>, <class '__main__.B'>]
顯然,這不是我的本意。 在這方面有兩個問題:
Python 不太關心類名,這些將是不同的類,您只需要一種機制來保存和查找您想要的類。
class A:
def __repr__(self):
return f"{self.__class__.__name__} floor={self.floor}"
@classmethod
def create_subclass(cls, name, attrs):
return type(name, (cls,), attrs)
di_cls = {}
#save them in a dictionary
for i in range(5):
di_cls[i] = A.create_subclass("B", {"func": abs, "floor" : i})
for i, cls in di_cls.items():
print(f"{cls()}")
class config:
#put them in hierarchical namespaces
cls_level1 = A.create_subclass("B", {"func": abs, "floor" : 11})
class level2:
cls_level2 = A.create_subclass("B", {"func": abs, "floor" : 22})
print(f"{config.cls_level1()=}")
print(f"{config.level2.cls_level2()}")
l1 = config.cls_level1()
l2 = config.level2.cls_level2()
print(f"{isinstance(l1, A)=}")
print(f"{isinstance(l2, A)=}")
print(f"{isinstance(l2, config.level2.cls_level2)=}")
print(f"{isinstance(l2, config.cls_level1)=}")
B floor=0
B floor=1
B floor=2
B floor=3
B floor=4
config.cls_level1()=B floor=11
B floor=22
isinstance(l1, A)=True
isinstance(l2, A)=True
isinstance(l2, config.level2.cls_level2)=True
isinstance(l2, config.cls_level1)=False
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