Python isinstance() built-in function
From the Python 3 documentation
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 a tuple of type objects (or recursively, other such tuples) or a Union Type of multiple types, return True if object is an instance of any of the types. If classinfo is not a type or tuple of types and such tuples, a TypeError exception is raised.
Introduction
The isinstance() function checks if an object is an instance of a particular class or a subclass of it. It returns True if the object is of the specified type, and False otherwise.
You can also check against a tuple of types.
Examples
Checking the type of an object:
my_list = [1, 2, 3]
print(isinstance(my_list, list)) # Output: True
print(isinstance(my_list, tuple)) # Output: False
Checking against multiple types:
print(isinstance("hello", (int, str, list))) # Output: True
>>> isinstance(1, int)
# True
>>> isinstance(1, str)
# False