Pandas SettingWithCopyWarning: A value is trying to be set on a copy of a slice from a DataFrame

Question

I keep getting the warning in the subject in the following situations:

1. df.rename(columns={\'one\':\'one_a\'}, inplace=True)

2. df.drop([\'one\'

Answer 1

Easiest fix (and probably good programming practice) would be to not do inplace operations, e.g.

df2 = df.rename(columns={'one':'one_a'})