title: Pandas not working: DataFrameGroupBy ; PanelGroupBy
body: <p>I have just upgraded python and I cannot get pandas to run properly, please see below. Nothing appears to work.</p>
  
  <blockquote>
    <p>Traceback (most recent call last):   File
    "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/tqdm/_tqdm.py",
    line 613, in pandas
        from pandas.core.groupby.groupby import DataFrameGroupBy, \ ImportError: cannot import name 'DataFrameGroupBy' from
    'pandas.core.groupby.groupby'
    (/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/pandas/core/groupby/groupby.py)</p>
  </blockquote>
  
  <p>During handling of the above exception, another exception occurred:</p>
  
  <blockquote>
    <p>Traceback (most recent call last):   File
    "code/analysis/get_cost_matrix.py", line 23, in 
        tqdm.pandas() # Gives us nice progress bars   File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/tqdm/_tqdm.py",
    line 616, in pandas
        from pandas.core.groupby import DataFrameGroupBy, \ ImportError: cannot import name 'PanelGroupBy' from 'pandas.core.groupby'
    (/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/pandas/core/groupby/<strong>init</strong>.py)</p>
  </blockquote>