Why is the second output not 2 2 2 and the third output not 3 3 3? What is the reason behind such output?
class A(object):
val = 1
class B(A):
pass
class C(A):
pass
print (A.val, B.val, C.val)
B.val = 2
print (A.val, B.val, C.val)
A.val = 3
print (A.val, B.val, C.val)
You initialize all the classes using A() soo A.val, B.val, C.val all refer to the same value 1 (1 1 1)
当你修改B.val = 2 so升值时,A.val和C.val的数值保持不变(1 2 1)
接下来,你修改A.val = 3 Soo A.val = 3,由于C.val正在从A继承,C.A.A.的继承也开始。 3. 但是,B.val仍然是2个,因为它有自己的阀子,从A.val(3 2 3)中分离出来。
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