对Pandas DataFrames进行排序

Question

我有一个带有汽车数据的Pandas Dataframe.我想为每个制造商找到最畅销的两个型号,然后对制造商进行排名,降序.

Maker   Model   No Sold(,000s)
Ford    Kuga    35
Ford    Focus   47
Ford    Ka          31
Ford    Fiesta      68
Ford    Mondeo      55
Ford    S-Max       34
Ford    Galaxy      23
Nissan  Leaf        28
Nissan  Micra       31
Nissan  Note            43
Nissan  Pulsar      23
Nissan  Juke            57
Nissan  Qashqai     62
Nissan  X-Trail         38
Honda   Jazz            24
Honda   Civic           32
Honda   HRV         33
Honda   CRV         29
Honda   Accord          30
Honda   NSX         15
Toyota  Aygo            44
Toyota  Auris           45
Toyota  Avensis         35
Toyota  Prius           32
Toyota  Rav4            29
Toyota  Land Cruiser    14
Citroen C1          40
Citroen C3  25
Citroen C4  46
Citroen DS3 35    
Citroen DS4 31
Citroen DS5 25    
Audi    A1  23
Audi    A3  47
Audi    A4  30
Audi    A6  20
Audi    A8  18
BMW 1 Series    36
BMW 2 Series    20
BMW 3 Series    53
BMW 4 Series    21
BMW 5 Series    27
BMW 6 Series    24
BMW 7 Series    16

对不起,不知道如何将Dataframe放在这里.

Answer 1

用groupby+nlargest

df.set_index('Model').groupby('Maker')['No Sold(,000s)'].nlargest(2)

Maker    Model  
Audi     A3         47
         A4         30
Citroen  C4         46
         C1         40
Ford     Fiesta     68
         Mondeo     55
Honda    HRV        33
         Civic      32
Nissan   Qashqai    62
         Juke       57
Toyota   Auris      45
         Aygo       44
Name: No Sold(,000s), dtype: int64