change specific columns of data frame using pandas

Question

I have a data frame 3 columns: [" date ", " volume ", " ID "]. ID=0,1,2...15. I would like to create new data frame: keep all rows with ID=5 .

Other rows: still keep them all, but set the row["volume"] = 0 .

Answer 1

First copy your dataframe:

df_new = df.copy()

Then, using pd.DataFrame.loc , set volume to 0 for your criteria:

df_new.loc[df_new['ID'] != 5, 'volume'] = 0