注：对图中第三点补充 同一对象内 相同数值不会重复开辟空间

代码如下：

a = b = 100

class Test1:
    a = 100
    b = 1000
    c = 1000

class Test2:
    a = 100
    b = 1000

print(a==b==Test2.a==Test1.a)#True
print(a is b)#True
print(Test1.a is b)#True
print(Test1.a is Test2.a)#True
print(Test1.b is Test1.c)#True
print(Test1.b is Test2.b)#False