python - 根据多列和一列的总和重新排序 pandas 数据框

Question

我有以下内容。数据框:

              Country_FAO            type   mean_area
0             Afghanistan             car   2029000.0
1             Afghanistan             car    112000.0
2                 Algeria             bus    827000.0
3                 Algeria             bus      2351.0
4               Australia             car   6475695.0
5               Australia             car  12141000.0
6               Australia             bus    293806.0

我想根据 Country_FAO 列中每个值的 mean_area 总和重新排序此数据框。最终结果应如下所示:

              Country_FAO            type   mean_area
0               Australia             car  12141000.0
1               Australia             car   6475695.0
2               Australia             bus    293806.0
3             Afghanistan             car   2029000.0
4             Afghanistan             car    112000.0
5                 Algeria             bus    827000.0
6                 Algeria             bus      2351.0

澳大利亚排名第一，因为其 3 个类别的 mean_area 值之和最高。

我尝试过这个:

df_stacked.sort(['Country_FAO', 'mean_area'], ascending=[False, False])

但这不起作用，它在排序之前不会将所有 mean_area 相加。

Answer 1

我认为您需要按 groupby 创建新列排序与 transform然后sort_values 。最后你可以drop它与 reset_index :

df['sort'] = df.groupby('Country_FAO')['mean_area'].transform(sum)

df['sort'] = df.groupby('Country_FAO')['mean_area'].transform(sum)

df1 = df.sort_values(['sort','Country_FAO', 'mean_area'], ascending=False)
print df1
   Country_FAO type   mean_area        sort
5    Australia  car  12141000.0  18910501.0
4    Australia  car   6475695.0  18910501.0
6    Australia  bus    293806.0  18910501.0
0  Afghanistan  car   2029000.0   2141000.0
1  Afghanistan  car    112000.0   2141000.0
2      Algeria  bus    827000.0    829351.0
3      Algeria  bus      2351.0    829351.0

df1 = df1.drop('sort', axis=1).reset_index(drop=True)
print df1
   Country_FAO type   mean_area
0    Australia  car  12141000.0
1    Australia  car   6475695.0
2    Australia  bus    293806.0
3  Afghanistan  car   2029000.0
4  Afghanistan  car    112000.0
5      Algeria  bus    827000.0
6      Algeria  bus      2351.0