This was happening with pandas==0.25.3
Updated to the latest pandas==1.2.1
UPDATE:
This was due to a numpy package 1.20.0,
so I locked the numpy package instead, numpy==1.19.5, pandas==0.25.3
This was happening with pandas==0.25.3
Updated to the latest pandas==1.2.1
UPDATE:
This was due to a numpy package 1.20.0,
so I locked the numpy package instead, numpy==1.19.5, pandas==0.25.3