What ~ in isin pandas method means&
~ Operator performs a not logical operation bitwise, which means it takes a set of data and negates the condition that you are performing on your dataframe.
In your case, df.index.isin(df_to_remove)  will return a certain set of values, like [True, False, True...]
With ~ operator, the output would be the logical  negation, [False, True, False...] or just the negation of the original condition.
filtered_df = df[~df.index.isin(df_to_remove)]
What does this ~ reduction mean?
Found it in answers to the task? Was written by smn smart