python中如何检验一个对象是否为某一个类的实例？

用isinstance函数来实现

比如如何检验一个对象是否是str类的实例

再比如如何检验一个对象是否是int类的实例

还可以检验一个对象是否是某几个实例中的一个

应用如下

isinstance(1,(list,int,str))

Out[21]: True

In [22]: help(isinstance)

Help on built-in function isinstance in module builtins:

isinstance(obj, class_or_tuple, /)

Return whether an object is an instance of a class or of a subclass thereof.

A tuple, as in ``isinstance(x, (A, B, ...))``, may be given as the target to

check against. This is equivalent to ``isinstance(x, A) or isinstance(x, B)

or ...`` etc.

isinstance可以检查一个对象是否是一个类的实例或者是一个类集合里面的实例。