逐行比较两个单独的熊猫数据帧并返回匹配值

Question

I have two pandas data frames df1 and df2. df1 contains 2 columns and 750 rows, df2 has 2 columns and 88 rows. I want to compare the two data frames and return the values from df1 that are present in df2 and store the matching values in a new column in df2. Ex.

df1

    A            B
    emp_table    emp_id
    emp_table    emp_name 
    pay_table    basic_amount
    pay_table    da_amount

df2
A              B
emp_table      emp_id
emp_table      emp_department
pay_table      da_amount

I want to add another column in df2 which has the matching values.

df2
A           B
emp_table   emp_id
pay_table   da_amount

I want to perform one to many comparison of each element of df1 with each element of df2.

Answer 1

I think you need merge without parameter on , so all columns are joined:

df = pd.merge(df1, df2)
print (df)
           A          B
0  emp_table     emp_id
1  pay_table  da_amount