gistfile1.txt

import pandas as pd

class ExtendedDF(pd.DataFrame):
    def __init__(self, df: pd.DataFrame):
        self.title = 'some dataframe'
        super().__init__(df)

somedf = pd.DataFrame()
extdf = ExtendedDF(df=somedf)

produces

Traceback (most recent call last):
  File "/Users/chepner/tmp.py", line 9, in <module>
    extdf = ExtendedDF(df=somedf)
  File "/Users/chepner/tmp.py", line 5, in __init__
    self.title = 'some dataframe'
  File "/nix/store/96rbddcm9zswxvx3p2l3dn5f86sfwd20-python3-3.9.5-env/lib/python3.9/site-packages/pandas/core/generic.py", line 5490, in __setattr__
    existing = getattr(self, name)
  File "/nix/store/96rbddcm9zswxvx3p2l3dn5f86sfwd20-python3-3.9.5-env/lib/python3.9/site-packages/pandas/core/generic.py", line 5463, in __getattr__
    if self._info_axis._can_hold_identifiers_and_holds_name(name):
  File "/nix/store/96rbddcm9zswxvx3p2l3dn5f86sfwd20-python3-3.9.5-env/lib/python3.9/site-packages/pandas/core/generic.py", line 5463, in __getattr__
    if self._info_axis._can_hold_identifiers_and_holds_name(name):
  File "/nix/store/96rbddcm9zswxvx3p2l3dn5f86sfwd20-python3-3.9.5-env/lib/python3.9/site-packages/pandas/core/generic.py", line 5463, in __getattr__
    if self._info_axis._can_hold_identifiers_and_holds_name(name):
  [Previous line repeated 987 more times]
  File "/nix/store/96rbddcm9zswxvx3p2l3dn5f86sfwd20-python3-3.9.5-env/lib/python3.9/site-packages/pandas/core/generic.py", line 547, in _info_axis
    return getattr(self, self._info_axis_name)
  File "/nix/store/96rbddcm9zswxvx3p2l3dn5f86sfwd20-python3-3.9.5-env/lib/python3.9/site-packages/pandas/core/generic.py", line 5461, in __getattr__
    return object.__getattribute__(self, name)
  File "pandas/_libs/properties.pyx", line 62, in pandas._libs.properties.AxisProperty.__get__
  File "/nix/store/96rbddcm9zswxvx3p2l3dn5f86sfwd20-python3-3.9.5-env/lib/python3.9/site-packages/pandas/core/generic.py", line 5461, in __getattr__
    return object.__getattribute__(self, name)
RecursionError: maximum recursion depth exceeded while calling a Python object

Same if I try with Python 3.8.