Python’s built-in isinstance(object, class) function takes an object and a class as input arguments. It returns True if the object is an instance of the class. Otherwise, it returns False. Instead of a class, you can also pass a tuple of classes to check if the object is an instance of any of the classes in the tuple—such as in isinstance(object, (class_A, class_B, ...)).
Usage
Learn by example! Here’s an example on how to use the isinstance() built-in function.
>>> isinstance(42, int)
True
>>> isinstance(42, (float, list, int))
True
>>> isinstance('42', (float, list, int))
FalseVideo isinstance()
Syntax isinstance()
The isinstance() method has the following syntax:
Syntax: isinstance(object, class) # Check if object is instance of class isinstance(object, (class_A, class_B, ...)) # Check if object is instance of any of the classes in the tuple
| Arguments | object | Object that should be checked for class membership. |
class or tuple of classes | Class or tuple of classes this object may or may not belong to. | |
| Return Value | Boolean | Returns whether the object belongs to the class (or the classes) or not. |
Return value from isinstance()
The isinstance(object, class) method returns True if the object is an instance of the class. Otherwise, it returns False.
Interactive Shell Exercise: Understanding isinstance()
Consider the following interactive code:
Exercise: Guess the output of this code snippet. Only then execute and test if you were right!
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Summary
Python’s built-in isinstance(object, class) function takes an object and a class as input arguments.
- It returns
Trueif theobjectis an instance of the class. - Otherwise, it returns
False.
>>> isinstance(42, int) True >>> isinstance(42, float) False
Instead of a class, you can also pass a tuple of classes to check if the object is an instance of any of the classes in the tuple—such as in isinstance(object, (class_A, class_B, ...)).
>>> isinstance(42, (float, list, int)) True
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