[Python] AttributeError: object has no attribute dataclass python3.11

from dataclasses import dataclass, field
from datetime import datetime
from typing import List as PyList
import json

@dataclass
class metadata:
docType:str

@dataclass
class spr:
sprType:str

@dataclass
class nMI:
idx:int

@dataclass
class bene:
bid:int
put:str

@dataclass
class ttd(metadata,spr,nMI):
bn:list[bene]


json_str = '''{
"docType":"abc",
"sprType":"def",
"idx":2,
"bn":[{
"bid":3, "put":"out"}]
}'''

def printMethod(t:metadata):
print(t)

def printMethod1(t:spr):
print(t)

def processMethod(t:ttd):
printMethod(t.metadata)
printMethod1(t.spr)


data = json.loads(json_str)

t=ttd(**data)

print(t)
# this prints the dictionary correctly

# ttd(idx=2, sprType='def', docType='abc', bn=[{'bid': 3, 'put': 'out'}])

processMethod(t)



I am getting a json value and deserializing in to objects using dataclass. In processMethod I am getting this error AttributeError: 'ttd' object has no attribute 'metadata'. Any suggestions please. I wanted to store the values in separate objects for ease of processing. I am not really familiar with inheritance and dataclasses and this in python 3.11

Continue reading...