how to merge dataframes of different sizes based on equal names when they appear more than once?

Question

I have a pandas dataframe like bellow:

name    day
joe      1
paul     1
paul     2
joe      2
peter    2

and another one:

name    zip_code
joe      1000
paul     1001
peter    2002

I need to join the zip_code column to them and result on this:

name    day   zip_code
joe      1      1000
paul     1      1001
paul     2      1001
joe      2      1000
peter    2      2002

Answer 1

Use df.merge:

df = df1.merge(df2)

Output:

    name  day  zip_code
0    joe    1      1000
1    joe    2      1000
2   paul    1      1001
3   paul    2      1001
4  peter    2      2002