Pandas column name lookup

I have a function to change a column name in a pandas dataframe by searching another dataframe which has two columns, one to match the look up and one to use to rename the column. The dataframe with the list of names has 57 items. When I use a dataframe with all 57 columns, some are missed. When I single out the ones missed for testing, they work perfectly.

I can supply code and data if needed.

I can supply code and data if needed.

It’s needed, Les.