Suppose I have the two following data frames df_1 and df_2 and want to merge them with an additional column which states if the row is present in df_1,df_2 or both. Is there any way I could do this directly while using merge?
df_1
df_2
The data frame I would like to have:
Use parameter indicator in merge and for expected output add map by dict:
df = pd.merge(df1, df2, how='outer', indicator='origin')
print (df)
Index x y origin
0 20 5 8 left_only
1 35 4 7 left_only
2 55 3 2 both
3 60 12 1 both
4 22 4 3 right_only
5 30 12 6 right_only
d = {'left_only':'1', 'right_only':'2', 'both':'1 & 2'}
df['origin'] = df['origin'].map(d)
print (df)
Index x y origin
0 20 5 8 1
1 35 4 7 1
2 55 3 2 1 & 2
3 60 12 1 1 & 2
4 22 4 3 2
5 30 12 6 2
