Como usar o constructor em Python de forma fácil?
Python Class Constructors: Control Your Object Instantiation
Python’s Class Constructors and the Instantiation Process
- Python supports object-oriented programming.
- Classes are defined using the
class
keyword. - Classes have attributes for storing data and methods for providing behaviors.
- Objects or instances of a class can be created and initialized.
- The object construction or instantiation process is triggered by the class constructor.
- The instantiation process includes instance creation and instance initialization.
Object Initialization With .__init__()
- The
.__init__()
method is used for object initialization. - It is automatically called when a new object is created.
- It initializes the object’s attributes.
- Custom object initializers can be provided by defining the
.__init__()
method in a class. - Object initializers can be made more flexible by using default values or keyword arguments.
Object Creation With .__new__()
- The
.__new__()
method is used for object creation. - It is responsible for creating a new instance of the class.
- Custom object creators can be provided by defining the
.__new__()
method in a class. - Immutable built-in types can be subclassed using
.__new__()
to customize object creation. - Instances of a different class can be returned by overriding
.__new__()
. - Only a single instance can be allowed in a class by using a class attribute and overriding
.__new__()
. - The behavior of
collections.namedtuple
can be partially emulated by overriding.__new__()
.
Conclusion
- Class constructors and the instantiation process are fundamental in object-oriented programming.
- Python provides the
.__init__()
and.__new__()
methods for object initialization and creation. - Custom object initializers and creators can be defined to control the instantiation process.
- Understanding and customizing class constructors allows for more advanced control over object instantiation.