python - 使用循环查询 pandas 列

Question

我有以下 df:

    country  sport  score
0   ita      swim   15 
1   fr       run    25
2   ger      golf   37
3   ita      run    17
4   fr       golf   58
5   fr       run    35

我只对类别的某些元素感兴趣:

ctr = ['ita','fr']
sprt= ['run','golf']

我希望通过这样的方式来提取它们:

df[(df['country']== x for x in ctr)&(df['sport']== x for x in sprt)]

但是虽然它不会抛出任何错误，但它返回空..

有什么建议吗？我也尝试过:

df[(df['country']== {x for x in ctr})&(df['sport']== {x for x in sprt})]

编辑:

之所以要使用循环，是因为我实际上对每个组合的 3 个最高分感兴趣，我希望将其连接起来:

df1 = pd.concat(df[(df['country']== x for x in ctr)&(df['sport']== x for x in sprt)].sort_values(by=['score'],ascending=False).head(3))

Answer 1

使用双 Series.isin检查成员(member)资格:

df1 = df[(df['country'].isin(ctr))&(df['sport'].isin(sprt))]
print (df1)
  country sport  score
1      fr   run     25
3     ita   run     17
4      fr  golf     58
5      fr   run     35

df2 = df1.sort_values('score', ascending=False).groupby(['country','sport']).head(3)
print (df2)
  country sport  score
4      fr  golf     58
5      fr   run     35
1      fr   run     25
3     ita   run     17