Joining two tables with Pandas, on a columns where there are repeated values

Question

Looking to join two tables together (tables 1 and 2) to look like table 3. I tried using pandas join on the dataframes, but I keep getting errors for trying to join on columns with repeated values.

Ex:

Table 1

ID	A	B
1	A1	B1
2	A1	B1
2	A2	B2

Table 2

ID	Property
1	Property 1
1	Property 2
2	Property 1
2	Property 2
2	Property 3

Table 3 (expected output)

ID	A	B	Property
1	A1	B1	Property 1
1	A1	B1	Property 2
2	A1	B1	Property 1
2	A1	B1	Property 2
2	A1	B1	Property 3
2	A2	B2	Property 1
2	A2	B2	Property 2
2	A2	B2	Property 3
2	A3	B3	Property 1
2	A3	B3	Property 2
2	A3	B3	Property 3

You need to merge the dfs , what did you do? what error you got , you need to provide more info — eshirvana, May 10 '23 at 13:39

score 0 · Answer 1 · answered May 10 '23 at 13:39

To merge them you can use merge method:

out = pd.merge(df1, df2, on='ID')

output:

>>>
   ID   A   B    Property
0   1  A1  B1  Property 1
1   1  A1  B1  Property 2
2   2  A1  B1  Property 1
3   2  A1  B1  Property 2
4   2  A1  B1  Property 3
5   2  A2  B2  Property 1
6   2  A2  B2  Property 2
7   2  A2  B2  Property 3

Joining two tables with Pandas, on a columns where there are repeated values

1 Answers1