如何将DataFrame列值映射至另一DataFrame双列并提取匹配行

Got it, I see where the issue was—your original code uses the logical OR (|) operator, which keeps any row where either G1 or G2 is in df1's NAME list. What you need is the logical AND (&) operator, which will only keep rows where both G1 and G2 are present in df1['NAME'].

Step-by-Step Fix: #

1. Replace the | with & in your boolean indexing to enforce both columns match the NAME values:

   # Corrected filtering code
   filtered_df = df2[(df2['G1'].isin(df1['NAME'])) & (df2['G2'].isin(df1['NAME']))]
   

2. This works because:

   • df2['G1'].isin(df1['NAME']) checks if the G1 value exists in df1's NAME column
   • df2['G2'].isin(df1['NAME']) does the same for G2
   • The & operator ensures both conditions are true for a row to be kept

Expected Output: #

Running the corrected code will give you exactly the rows you're looking for:

G1     G2  Value
0   AB2    AB3      5
1   AB3    AB2      5
2   AB2    AB2      4
5   AB5    AB6      4
10 AB776 AB776      1
11 AB845 AB776      8

内容的提问来源于stack exchange，提问作者user2110417