python - 基于两列比较两个数据帧并打印匹配值并对匹配值进行分组

Question

我有两个这样的数据框，

>>df1
  name key1 key2   A   B
0  a1  1    K0   A0   B0
1  a2  2    K1   A1   B1
2  a3  3    K0   A2   B2
3  a3  4    K1   A3   B3

>>df2
  key1 key2 
0   1   K0  
1   2   K0  
2   3   0K  
3   4   1K  

我需要将 df1 的 key1,key2 与 df2 进行比较，并且必须打印匹配的行。比较时我必须检查 df1['key1','key2'] == df2['key1','key2'] 或 df1['key1','key2'] == df2['key1',reverse(' key2')]

预期输出:

>>df3
      name key1 key2   A   B  
       a1  1    K0   A0   B0  
       a3  3    K0   A2   B2  
       a3  4    K1   A3   B3  
>>df4
      name key1 key2   A      B      
       a1  1    K0     A0     B0     
       a3  3,4  K0,K1  A2,A3  B2,B3  

Answer 1

尝试:

x = df1.merge(df2, on=["key1", "key2"])
df2["key2"] = df2["key2"].str[::-1]
y = df1.merge(df2, on=["key1", "key2"])

df3 = pd.concat([x, y])
df4 = (
    df3.assign(key1=df3.key1.astype(str))
    .groupby("name", as_index=False)
    .agg(", ".join)
)

print(df3)
print(df4)

打印:

  name  key1 key2   A   B
0   a1     1   K0  A0  B0
0   a3     3   K0  A2  B2
1   a3     4   K1  A3  B3

  name  key1    key2       A       B
0   a1     1      K0      A0      B0
1   a3  3, 4  K0, K1  A2, A3  B2, B3