drop_duplicates not working in pandas?

Question

The purpose of my code is to import 2 Excel files, compare them, and print out the differences to a new Excel file.

However, after concatenating all the data, and us

Answer 1

Might help anyone in the future.

I had a column with dates, where I tried to remove duplicates without success. If it's not important to keep the column as a date for further operations, I converted the column from type object to string.

df = df.astype('str')

Then I performed @Keith answers

df = df.drop_duplicates(subset=None, keep="first", inplace=True)