import pandas as pd
from typing import TypeVar, Generic
from dataclasses import dataclass

DataclassType = TypeVar("DataclassType")

class TypedDataFrame(pd.DataFrame, Generic[DataclassType]):    
    _metadata = ['typevar']

    @classmethod
    def _internal_ctor(cls, *args, **kwargs):
        kwargs['typevar'] = None
        return cls(*args, **kwargs)

    def __init__(self, *args, **kwargs):
        if "typevar" in kwargs:
            self.typevar = kwargs["typevar"]
            del kwargs["typevar"]
        else:
            self.typevar = None
        super(TypedDataFrame, self).__init__(*args, **kwargs)
        
    def __repr__(self):
        return f"{self.typevar.__name__}\n{pd.DataFrame(self).__repr__()}"
        


@dataclass
class ABCD:
    a: int
    b: int


df2 = TypedDataFrame([ABCD(1,2), ABCD(3,4)], typevar=ABCD)

def get_df(df: TypedDataFrame[ABCD]):
    return df