Question

我已经设置了一个DataFrame，以便将一列国家/地区名称设置为索引列。我想更改该索引列的标题。这似乎是一件简单的事情，但我无法找到如何实际做到这一点。怎么做到呢？指数＆＃34;食品＆＃34;此处的列更改为＆＃34;国家＆＃34;？

import pandas as pd

df = pd.DataFrame(
    [
        ["alcoholic drinks"  ,  375,  135,  458,  475],
        ["beverages"         ,   57,   47,   53,   73],
        ["carcase meat"      ,  245,  267,  242,  227],
        ["cereals"           , 1472, 1494, 1462, 1582],
        ["cheese"            ,  105,   66,  103,  103],
        ["confectionery"     ,   54,   41,   62,   64],
        ["fats and oils"     ,  193,  209,  184,  235],
        ["fish"              ,  147,   93,  122,  160],
        ["fresh fruit"       , 1102,  674,  957, 1137],
        ["fresh potatoes"    ,  720, 1033,  566,  874],
        ["fresh Veg"         ,  253,  143,  171,  265],
        ["other meat"        ,  685,  586,  750,  803],
        ["other veg."        ,  488,  355,  418,  570],
        ["processed potatoes",  198,  187,  220,  203],
        ["processed veg."    ,  360,  334,  337,  365],
        ["soft drinks"       , 1374, 1506, 1572, 1256],
        ["sugars"            ,  156,  139,  147,  175]
    ],
    columns = [
        "foods",
        "England",
        "Northern Ireland",
        "Scotland",
        "Wales"
    ]
)

df = df.set_index("foods")

df = df.transpose()
df = df.rename({"foods": "countries"})
df

Answer 1

试试这个：

df = df.rename_axis("countries", axis=0).rename_axis(None, axis=1)

演示：

In [10]: df
Out[10]:
                  alcoholic drinks  beverages  carcase meat   ...
countries
England                        375         57           245
Northern Ireland               135         47           267
Scotland                       458         53           242
Wales                          475         73           227

Answer 2

food是您的列索引名称，而不是您的索引名称。

你可以像这样明确地设置它：

df.index.name = 'countries'

输出：

foods             alcoholic drinks  beverages  carcase meat  cereals  cheese  \
countries                                                                      
England                        375         57           245     1472     105   
Northern Ireland               135         47           267     1494      66   
Scotland                       458         53           242     1462     103   
Wales                          475         73           227     1582     103

并且，要从列索引名称中删除food：

df.columns.name = None

输出：

                  alcoholic drinks  beverages  carcase meat  cereals  cheese  \
countries                                                                      
England                        375         57           245     1472     105   
Northern Ireland               135         47           267     1494      66   
Scotland                       458         53           242     1462     103   
Wales                          475         73           227     1582     103

Answer 3

Pandas有Index.rename() method.这样的作品：

import pandas as pd

df = pd.DataFrame(
    [
        ["alcoholic drinks", 375, 135, 458, 475],
        ["beverages", 57, 47, 53, 73],
        ["carcase meat", 245, 267, 242, 227],
        ["cereals", 1472, 1494, 1462, 1582],
        ["cheese", 105, 66, 103, 103],
        ["confectionery", 54, 41, 62, 64],
        ["fats and oils", 193, 209, 184, 235],
        ["fish", 147, 93, 122, 160],
        ["fresh fruit", 1102, 674, 957, 1137],
        ["fresh potatoes", 720, 1033, 566, 874],
        ["fresh Veg", 253, 143, 171, 265],
        ["other meat", 685, 586, 750, 803],
        ["other veg.", 488, 355, 418, 570],
        ["processed potatoes", 198, 187, 220, 203],
        ["processed veg.", 360, 334, 337, 365],
        ["soft drinks", 1374, 1506, 1572, 1256],
        ["sugars", 156, 139, 147, 175]
    ],
    columns=[
        "foods",
        "England",
        "Northern Ireland",
        "Scotland",
        "Wales"
    ]
)

df.set_index('foods', inplace=True)
df = df.transpose()

print(df.head())

foods             confectionery  fats and oils  fish  fresh fruit ...
England                      54            193   147         1102
Northern Ireland             41            209    93          674
Scotland                     62            184   122          957
Wales                        64            235   160         1137

重命名DataFrame的索引：

df.index.rename('Countries', inplace=True)
print(df.head())

foods             confectionery  fats and oils  fish  fresh fruit ...
    Countries
England                      54            193   147         1102
Northern Ireland             41            209    93          674
Scotland                     62            184   122          957
Wales                        64            235   160         1137

由于transpose()，构成列的基础系列现在具有名称。我们需要做的就是将其重命名为空字符串：

df.columns.rename('', inplace=True)
print(df.head())

                  confectionery  fats and oils  fish  fresh fruit ...
    Countries
England                      54            193   147         1102
Northern Ireland             41            209    93          674
Scotland                     62            184   122          957
Wales                        64            235   160         1137

Answer 4

我不喜欢这个超过@ MaxU的答案，因为它的速度较慢，但对于任何值得的代码来说它都是更短的代码。

df.stack().rename_axis(['countries', None]).unstack()

                  alcoholic drinks  beverages  carcase meat  cereals
countries                                                           
England                        375         57           245     1472
Northern Ireland               135         47           267     1494
Scotland                       458         53           242     1462
Wales                          475         73           227     1582

如何更改pandas DataFrame的索引列的名称？

4 个答案: