Cannot describe a DataFrame without columns

two days ago, I did a short data analysis on a certain dataset. Today, I want to built upon this work on a different project. So I copy-pasted some of the code, while for the project I am starting today the code worked just fine, the project from two days ago is running into following error.

It wouldbe great if someone could explain me what the problem is and how to solve it, because I ran into this before. Back then I solved it by creating a new code-sheet, which should not be the way to go, since I want to run the code several time without always creating a new notebook.

what I am working with:

Jupyter Notebook

Python 3.6 (in a virt env)

Linux 22.04

You find screenshots of both codes and outputs in the following: Input-Output 1 Input-Output 2

Best regards, Solaris

categorical_features = dtype[dtype == 'object'].index

readable_df[numerical_features].describe()
# Split features into categorical and numerical, print numerical
dtype = readable_df.dtypes
numerical_features = dtype[dtype == 'int64'].index
categorical_features = dtype[dtype == 'object'].index
​
readable_df[numerical_features].describe()
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
Input In [7], in <cell line: 6>()
      3 numerical_features = dtype[dtype == 'int64'].index
      4 categorical_features = dtype[dtype == 'object'].index
----> 6 readable_df[numerical_features].describe()

File ~/python-env/python-env/lib/python3.9/site-packages/pandas/core/generic.py:10227, in NDFrame.describe(self, percentiles, include, exclude, datetime_is_numeric)
   9978 @final
   9979 def describe(
   9980     self: NDFrameT,
   (...)
   9984     datetime_is_numeric=False,
   9985 ) -> NDFrameT:
   9986     """
   9987     Generate descriptive statistics.
   9988 
   (...)
  10225     max            NaN      3.0
  10226     """
> 10227     return describe_ndframe(
  10228         obj=self,
  10229         include=include,
  10230         exclude=exclude,
  10231         datetime_is_numeric=datetime_is_numeric,
  10232         percentiles=percentiles,
  10233     )

File ~/python-env/python-env/lib/python3.9/site-packages/pandas/core/describe.py:87, in describe_ndframe(obj, include, exclude, datetime_is_numeric, percentiles)
     82     describer = SeriesDescriber(
     83         obj=cast("Series", obj),
     84         datetime_is_numeric=datetime_is_numeric,
     85     )
     86 else:
---> 87     describer = DataFrameDescriber(
     88         obj=cast("DataFrame", obj),
     89         include=include,
     90         exclude=exclude,
     91         datetime_is_numeric=datetime_is_numeric,
     92     )
     94 result = describer.describe(percentiles=percentiles)
     95 return cast(NDFrameT, result)

File ~/python-env/python-env/lib/python3.9/site-packages/pandas/core/describe.py:164, in DataFrameDescriber.__init__(self, obj, include, exclude, datetime_is_numeric)
    161 self.exclude = exclude
    163 if obj.ndim == 2 and obj.columns.size == 0:
--> 164     raise ValueError("Cannot describe a DataFrame without columns")
    166 super().__init__(obj, datetime_is_numeric=datetime_is_numeric)

ValueError: Cannot describe a DataFrame without columns