Get class name as string in Python

Introduction

Python is a versatile and powerful programming language that offers various tools to manipulate data and objects. One common task in Python is to retrieve the name of a class as a string. Knowing the class name as a string can be helpful in scenarios like debugging, logging, or dynamic class instantiation. In this blog, we'll explore different methods to obtain the class name as a string with example codes and detailed explanations.

Python get class name as string using __class__.__name__

In Python, every class is derived from the object class. The __class__ attribute is a reference to the class from which an object is created. We can use this attribute to retrieve the class name as a string using the __name__ attribute.

class Dog:
    def __init__(self, name):
        self.name = name

    def get_class_name(self):
        return self.__class__.__name__

# Create an instance of the Dog class
dog_instance = Dog("Buddy")

# Get the class name as a string
class_name = dog_instance.get_class_name()

# Output the result
print("Class Name:", class_name)  # Output: Class Name: Dog

In this example, we defined a simple class called "Dog" with an instance method get_class_name(). Inside this method, we use self.__class__.__name__ to retrieve the class name as a string. When we create an instance of the Dog class and call the get_class_name() method on it, the output will be: Class Name: Dog

Python get class name as string using type() and name attribute

Another method to obtain the class name as a string is by using the type() function along with the __name__ attribute. The type() function returns the type of an object, which in this case, is our class. The __name__ attribute then provides the class name as a string.

class Cat:
    def __init__(self, name):
        self.name = name

# Create an instance of the Cat class
cat_instance = Cat("Whiskers")

# Get the class name as a string using type() and __name__
class_name = type(cat_instance).__name__

# Output the result
print("Class Name:", class_name)  # Output: Class Name: Cat

In this example, we defined a class "Cat" and created an instance named "cat_instance." Using type(cat_instance).__name__, we retrieve the class name as a string.

Python get class name as string using nested classes

Python allows us to define classes within other classes, known as nested classes. When dealing with nested classes, we can use the __qualname__ attribute to obtain the fully-qualified name of the class as a string. The fully-qualified name includes the names of all enclosing classes, separated by dots.

class Car:
    def __init__(self, make):
        self.make = make

    class Engine:
        def __init__(self, horsepower):
            self.horsepower = horsepower

# Create an instance of the nested class Engine
engine_instance = Car.Engine(horsepower=200)

# Get the fully-qualified class name as a string using __qualname__
class_name = engine_instance.__class__.__qualname__

# Output the result
print("Class Name:", class_name)  # Output: Class Name: Car.Engine

In this example, we have a class "Car" containing a nested class "Engine." We create an instance of the Engine class and use engine_instance.__class__.__qualname__ to obtain the fully-qualified class name.

Conclusion

In this blog post, we explored three different methods to get the class name as a string in Python. The first method, __class__.__name__, provided a direct and simple approach, perfect for most scenarios. The second method, using type() and __name__, offered an alternative way to achieve the same result. Lastly, we delved into dealing with nested classes and how the __qualname__ attribute can give us the fully-qualified class name.

Understanding these techniques will empower you to work effectively with class names in your Python projects.