Python IsInstance Example | Python isinstance() Function

Python isinstance() is an inbuilt method that returns True if a specified object is of the specified type, otherwise, it returns False. If the type parameter is the tuple, this function will return True if the object is one of the types in the tuple.

The isinstance() function checks if the object which is the first argument is an instance or subclass of classinfo class which is the second argument.

Python IsInstance Example

The syntax of the Python isinstance() method is the following.

isinstance(object, classinfo)

The object parameter is required, and it is an object that needs to be checked.

A classinfo or a class, or a tuple of types and classes.

If classinfo is not a type or tuple of types, a TypeError exception is raised.

See the following example.

# app.py

class App:
  GoT = 'Aegon'
  
series = App()

print(isinstance(series, App))
print(isinstance(series, (list, tuple)))
print(isinstance(series, (list, tuple, App)))

The output of the above code is following.

Let’s see other examples.

# app.py

numbers = [19, 21, 46]

result = isinstance(numbers, list)
print(numbers,'instance of list?', result)

result = isinstance(numbers, dict)
print(numbers,'instance of dict?', result)

result = isinstance(numbers, (dict, list))
print(numbers,'instance of dict or list?', result)

number = 21

result = isinstance(number, list)
print(number,'instance of list?', result)

result = isinstance(number, int)
print(number,'instance of int?', result)

The output is the following.

Check if “AppDividend” is one of the types described in the type parameter.

# app.py

xyz = isinstance("AppDividend", (float, int, str, list, dict, tuple))
print(xyz)

The output is the following.

#type() in Python

Python has a built-in method called a kind which generally comes in handy while figuring out the type of the variable used in the program in the runtime.

If a single argument (object) is passed to type() built-in, it returns the type of the given object.

If three arguments (name, bases, and dict) are passed, it returns a new type object. See the following example of the type() function.

# app.py

a = 10
b = "AppDividend"
c = [19,21,46] 
print(type(a)) 
print(type(b)) 
print(type(c))

The output is the following.

#More Examples

Check if “AppDividend” is one of the types described in the type parameter.

# app.py

x = isinstance("AppDividend", (float, int, str, list, dict, tuple))
print(x)

The AppDividend value is a type of String, which is included in the second parameter. So it will return True. Otherwise, it would have return False. The other types are float, int, list, dict, and tuple.

#type() vs. isinstance()

Python type() simply returns the type object of an object and comparing what it returns to another type object will only yield True when you use the exact same type object on both sides.

Python isinstance() will help you if you’re checking to see if an object has a certain type.

In Python, it’s preferable to use the Duck Typing( type checking be deferred to run-time, and is implemented by means of dynamic typing or reflection) rather than inspecting the type of an object.

Conclusively, Python IsInstance Example | Python isinstance() Function Tutorial is over.

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