```python In [5]: pd.DataFrame(columns=['a', 'a', 'b']) Out[5]: Empty DataFrame Columns: [a, b] Index: [] In [6]: pd.DataFrame.from_records({}, columns=['a', 'a', 'b']) Out[6]: Empty DataFrame Columns: [a, a, b] Index: [] ``` I don't know which is preferred. This is not being fixed in https://github.com/pandas-dev/pandas/pull/24387