面向对象之元类
num = 10
print(num.__class__)
s = "abc"
print(s.__class__)
class Person():
    pass
p = Person()
print(p.__class__)
print(int.__class__)
print(str.__class__)
print(Person.__class__)

num = 10
print(num.__class__)
s = "abc"
print(s.__class__)
class Person():
    pass
p = Person()
print(p.__class__)
print(int.__class__)
print(str.__class__)
print(Person.__class__)
