Easy Python: how to create your own class in a couple of lines with the dataclass module
Data analysts and Data Scientists like Python - an easy to-learn and to-use object-oriented language that contains many built-in functions and allows you to create your own. According to the DRY (Don’t Repeat Yourself) principle, the current development standard is to package code into classes that provide APIs for using their methods. In practice, you have to create your own classes in Python quite often, with the subsequent addition and expansion. You can do it faster with the standard module dataclasses, which should be imported first. Then you need to decorate the custom class with a special function dataclass, and list the necessary attributes inside this class, annotating them beforehand, i.e. by specifying the types. For example, for a custom class Person with an integer ID and string name, it would look like this:
from dataclass import dataclass
@dataclass
class Person:
id: int
name: str
The dataclasses module provides a decorator and functions to automatically add generated custom methods such as init () and repr () to user-defined classes. However, you need to use the dataclasses module wisely and be aware of the following features:
• by default, the module does not check the type specified in the variable annotation;
• the dataclass() decorator adds some methods to the custom class that may be redundant and duplicate the behavior of those already existing in the class;
• when using the dataclass() decorator, all base classes are viewed in reverse order, starting from the object, and for each class found, the attributes of its parent are added to the ordered display of the fields. All generated methods will use this combined computed ordered field mapping. And because the fields are in the order they are inserted, derived classes override base ones.