Python isinstance 返回 false。自定义类[关闭]

Question

我已经写了以下代码。

class Mammal:
    def info():
        return 'I have fur on my body.'

    def identity_mammal():
        print('I am a mammal')

class Primate(Mammal):
    def info():
        return Mammal.info() + ' I have a large brain.'

    def identity_primate():
        print('I am a primate')

class Ape(Primate):
    def info():
        return Primate.info() + ' I am monkey oooh oooh aaah aaah.'

    def identity_ape():
        print('I am an ape')

class Human(Primate):
    def info():
        return Primate.info() + ' I am human, me bipedal SMART monkey'

    def identity_human():
        print('I am a human')

John = Human

print(isinstance(John, Mammal))
print(isinstance(John, Primate))
print(isinstance(John, Human))
print(isinstance(John, Ape))

这是一个关于继承的简单任务，但是当我使用 isinstance 函数时，我刚刚创建的 Human 的实例似乎不是人类

[iveris@ic-rh7mnifi-105 oblig44]$ python3 inheritance.py 

False
False
False
False

Answer 1

要创建实例，需要使用括号：

John = Human()

print(isinstance(John, Mammal))
print(isinstance(John, Primate))
print(isinstance(John, Human))
print(isinstance(John, Ape))