Data classes

Fatma Kahveci
Coding
Page content
  • dataclass == python object
  • dataclass is mutable.
from dataclasses import dataclass

@dataclass
class Student:
  name: str
  id: int
  age: int = 10
  year: int = 5
  
  def birthday(self):
    self.age += 1
 
bob = Student("bob", 123)
bob.birthday() # age = 11
print(bob)

print(bob == ("bob", 123, 10, 5)) # False
print(dataclasses.astuple(bob) == ("bob", 123, 10, 5)) # True
  • dataclass can be made immutable.
from dataclasses import dataclass

@dataclass(frozen=True) # immutability
class Point:
  x: int
  y: int

origin = Point(0, 0)
# origin.x += 1 # it throws an error
origin.__dict__["x"] = 1 # to change the value of immutable