class-dataclass

data_class_example.py

class Device:
    
    def __init__(self,model_name, manufacturer, price, model_year):
        self.model_name = model_name
        self.manufacturer = manufacturer
        self.price = price
        self.model_year = model_year
        

phone1 = Device("Note 9","Samsung",1000,2020) 
phone2 = Device("Note 9","Samsung",1000,2020) 
phone3 = Device("11","Iphone",1200,2020) 

print(phone1) #<__main__.Device object at 0x7f97d1bb6ac0>
print(id(phone1)) #140290036085424
print(id(phone2)) #140290036085520
print(phone1 == phone2) #False

from dataclasses import dataclass, field

@dataclass(order=True, frozen=False)
class Device:
    sort_index: int = field(init=False,repr=False)
    model_name : str
    manufacturer : str
    price : int
    model_year : int
    inventory : bool = True #we can define default atts
    
    def __post_init__(self):
        """
        initializes after init
        """
        self.sort_index = self.price

phone1 = Device("Note 9","Samsung",1000,2020) 
phone2 = Device("Note 9","Samsung",1000,2020)
phone3 = Device("11","Iphone",1200,2020)

print(phone1) #Device(model_name='Note 9', manufacturer='Samsung', price=1000, model_year=2020)
print(id(phone1)) #140290036088736
print(id(phone2)) #140290036085424
print(phone1 == phone2) #True
print(phone3 > phone2) #True