Python check if isinstance any type in list?

Question

How do I pythonicly do:

var = 7.0
var_is_good = isinstance(var, classinfo1) or isinstance(var, classinfo2) or isinstance(var, classinfo3) or ... or  isinstance(v         


        

Answer 1

You were pretty close with the title of your question already. You could use any and a list:

var = 7.0
var_is_good = any([isinstance(var, classinfo1),
                   isinstance(var, classinfo2),
                   isinstance(var, classinfo3), ...
                   isinstance(var, classinfoN)])

But looking in the docs of isinstance reveals:

Return true if the object argument is an instance of the classinfo argument, or of a (direct, indirect or virtual) subclass thereof. If object is not an object of the given type, the function always returns false. If classinfo is not a class (type object), it may be a tuple of type objects, or may recursively contain other such tuples (other sequence types are not accepted). If classinfo is not a type or tuple of types and such tuples, a TypeError exception is raised.

This means the better way to do it is

var = 7.0
var_is_good = isinstance(var, (classinfo1,
                               classinfo2,
                               classinfo3,
                               ...,
                               classinfoN))