Error while trying to replace multiple values of a pandas data-frame column based on matching condition

I have a column in a pandas data frame, among other columns, as such:

     Remarks
   Left_only
  Right_only
   Left_only
  Right_only

For this column, I want to replace all Left_only values to Yesterday And Right_only To Today

I use this code line:

DF.loc[df[‘Remarks’] == ‘Left_only’, ‘Remarks’] = ‘Yesterday’

Similarly, for the other one. But I get this error:

Cannot setitem on a Categorical with a new category (Yesterday), set the categories first

What am I doing wrong ?

>Solution :

# create a dictionary to map the two values
d={'Left_only': 'Yesterday', 'Right_only':'Today'}
df['Remarks']=df['Remarks'].map(d)
df

0    Yesterday
1        Today
2    Yesterday
3        Today
Name: Remarks, dtype: object