Python - Immutable Struct

Using Python - Frozen dataclass:

• The simplest immutable structure:

from dataclasses import dataclass
 
@dataclass(frozen = True)
class simple_person:
	name: str
	surname: str
	ID: str
	hobbies: str = None #Optional Parameter
 
John = simple_person("John", "Carter", 102012)

• Structure with “laws” and an invisible parameter at declaration “immutable_metadata”

from dataclasses import dataclass
 
add_new_field = object.__setattr__
 
@dataclass(frozen=True)
class immutable_metadata:
	metadata1
	metadata2
 
@dataclass(frozen=True)
class Immutable:
	a: int
	b: int
	
	def __post_init__(self):
		print(type(self.a))
		if self.a is int: raise Exception
		if self.b is int: raise Exception
 
		metadata = immutable_metadata("porva","p")
 
		add_new_field(self, "metadata", metadata)
 
imm = Immutable(1,2)
print(imm.a)
print(imm.metadata.metadata1)
print(imm.metadata.metadata2)