Object property setters with “_” and “__” /u/Avivajpeyi Python Education

Can someone explain this behaviour to me? Specifically why ‘__a’ is nnot getting cached.

“`python class Foo():

@property def a(self): if not hasattr(self, “a”): print(“no cached ‘a’, assiging __a”) self.a=’a’ return self.__a

@property def b(self): if not hasattr(self, “_b”): print(“no cached ‘b’, assigning _b”) self._b=’b’ return self._b

f = Foo()

print(“Calling f.a”) print(f”f.a={f.a}”) print(f”f.a={f.a}”) print(“______________”) print(“Calling f.b”) print(f”f.b={f.b}”) print(f”f.b={f.b}”) “`

“` Calling f.a no cached ‘a’, assiging __a f.a=a no cached ‘a’, assiging __a f.a=a

Calling f.b no cached ‘b’, assigning _b f.b=b f.b=b

“`

Can someone explain this behaviour to me? Specifically why ‘__a’ is nnot getting cached.

“`python class Foo():

@property def a(self): if not hasattr(self, “a”): print(“no cached ‘a’, assiging __a”) self.a=’a’ return self.__a

@property def b(self): if not hasattr(self, “_b”): print(“no cached ‘b’, assigning _b”) self._b=’b’ return self._b

f = Foo()

print(“Calling f.a”) print(f”f.a={f.a}”) print(f”f.a={f.a}”) print(“______________”) print(“Calling f.b”) print(f”f.b={f.b}”) print(f”f.b={f.b}”) “`

“` Calling f.a no cached ‘a’, assiging __a f.a=a no cached ‘a’, assiging __a f.a=a

Calling f.b no cached ‘b’, assigning _b f.b=b f.b=b

“`