在这种情况下，如何正确使用df [df ['Event_gender'] =='X']？

Question

比方说：有一个数据框：

country       Edition     sports       Athletes           Medal  Event_gender
Germany          1990    Aquatics  HAJOS, Alfred          gold     X
Germany          1990    Aquatics  HIRSCHMANN, Otto       silver   X
Germany          1990    Aquatics  DRIVAS, Dimitrios      silver   M
US               2008    Athletics MALOKINIS, Ioannis     gold     M
US               2008    Athletics HAJOS, Alfred          silver   W
US               2009    Athletics CHASAPIS, Spiridon     gold     X
France           2010    Athletics CHOROPHAS, Efstathios  gold     X
France           2010    Athletics CHOROPHAS, Efstathios  gold     M
France           2010    golf      HAJOS, Alfred          silver   M
France           2011    golf      ANDREOU, Joannis       silver   W
Spain            2011    golf      BURKE, Thomas          gold     W

我想找出多少个国家获得了金牌，其赛事性别等于'X'？

所以我试图解决它，但我被卡住了。我做到了：

df[df['Medal']== 'gold']['country'].nunique() 

现在我已经获得了金牌的国家，但我在努力添加

df[df['Event_gender']== 'X']

根据以上逻辑获得最终结果。有人可以帮我吗？

Answer 1

IIUC，是

df.loc[(df['Medal']=='gold') & (df['Event_gender']=='X'), 'country'].nunique()