Answers for "pandas merging data based on two columns"

merge two dataframes based on column

df_outer = pd.merge(df1, df2, on='id', how='outer') #here id is common column

df_outer

pandas combine two data frames with same index and same columns

pd.merge(df1, df2, left_index=True, right_index=True, how='outer')

merge two columns pandas

df["period"] = df["Year"] + df["quarter"]