In this article, we will see How To Get a Class Name of a class instance.
For getting the class name of an instance, we have the following 4 methods that are listed below:
- Using the combination of the __class__ and __name__ to get the type or class of the Object/Instance.
- Use the type() function and __name__ to get the type or class of the Object/Instance.
- Using the decorator to get the type or class of the Object/Instance.
- Using nested classes to get the type or class of the Object/Instance.
Using __class__.__name__ to Get the Class Name of an Instance
__name__ is a special variable in Python. It is a built-in variable that evaluates the name of the current module. Thus, it can be used to check whether the current script is being run on its own or being imported somewhere else by combining it with the if statement.
Python3
# this is a class named carclass car: def parts(): passc = car()# prints the class of the object cprint(c.__class__)# this prints the name of the classclasses = c.__class__# prints the name of the classprint(classes.__name__) |
Output:
<class '__main__.car'> car
Using type() and __name__ attribute to Get the Class Name of an Instance
Also, we can also print the type of c (class car) which gives the object of c and __name__ provides the name of the class. __name__ is a built-in variable that evaluates the name of the current module.
Python3
# this is a class named carclass car: def parts(self): passc = car()# this prints the class of a cprint(type(c).__name__) |
Output:
car
Using a decorator to Get the Class Name of an Instance
Here, we used @property decorator in order to get a name other than a python method. To get more information about @property decorator, please refer to Python Property Decorator. The function which returns the name of the class
Python3
# class for getting the class nameclass test: @property def cls(self): return type(self).__name__a = test()print(a.cls) |
Output:
test
Using nested classes to Get the Class Name of an Instance
In this example, we can obtain the name of the class object by using the __qualname__ attribute rather than the __name__ attribute. The __qualname__ provides a dotted path to the target object’s name. When dealing with nested structures, such as when a method is contained within a class, using __qualname__ is beneficial.
Python3
class bike: def __init__(self, name, b): self.name = name self.car = self.car(b) class car: def __init__(self, car): self.car = carvehicle = bike("orange", ['potatoes'])print(vehicle.car.__class__.__name__)print(vehicle.car.__class__.__qualname__) |
Output:
car bike.car
Using the inspect module from the Python Standard Library:
The inspect module provides several functions for inspecting and introspecting Python objects, including the getmembers() function, which can be used to retrieve a list of all the members of an object, including its class name.
Here is an example of how you can use the inspect module to get the class name of an instance:
Python3
import inspectclass MyClass: passobj = MyClass()members = inspect.getmembers(obj)class_name = [m[1] for m in members if m[0] == '__class__'][0]print(class_name.__name__) # Output: 'MyClass' |
MyClass
This approach first imports the inspect module, and then defines a simple class called MyClass. An instance of MyClass is then created, and the getmembers() function is used to retrieve a list of all the members of the object. This list is then filtered to select only the __class__ member, and the class name is extracted from this member using indexing and the __name__ attribute. This approach can be useful if you need to get the class name of an instance in a more general way, and is not limited to just the methods mentioned in the article.
Using init_subclass() method:
Approach:
Step 1:Define a base class with the __init_subclass__() method. This method is called every time a subclass is created and can be used to modify the subclass.
Step 2: Define a subclass and inherit from the base class.
Step 3: Create an instance of the subclass.
Step 4: Access the name attribute of the instance.
Python3
class MyBaseClass: def __init_subclass__(cls, **kwargs): super().__init_subclass__(**kwargs) cls.name = cls.__name__class MyClass(MyBaseClass): passobj = MyClass()print(obj.name) |
MyClass
Time Complexity: O(1)
Space Complexity: O(1)
