小编Bri*_*eny的帖子

熊猫0.12.0

在下面的DataFrame中,为什么例如它混杂了索引？看看4,索引从1,15,6,7开始.大熊猫用什么来决定如何订购,我会怀疑索引在相同的值上保持顺序.

mydf=pd.DataFrame(np.random.randint(1, 6, 20),columns=["stars"])
mydf.sort(['stars'], ascending=False)


     stars
19   5
14   5
1    4
15   4
6    4
7    4
4    3
12   3
18   3
8    2
2    2
9    2
10   2
11   2
13   2
16   2
5    1
3    1
17   1
0    1

我有一个 DataFrame，它有一个空列“pred”，我希望用一些特定值更新它。它们最初位于 numpy 数组中，但我将它们放在一个名为“this”的系列中： print(type(predictions))

print(predictions)
['collection2' 'collection2' 'collection2' 'collection1' 'collection2'
 'collection1']

this = pd.Series(predictions, index=test_indices)

print(type(data))
<class 'pandas.core.frame.DataFrame'>

print(data.shape)
(35, 4)

print(data.iloc[test_indices])
     class         pred                                          text  \
223  collection2   []  Fellow-Citizens of the Senate and House of Rep...   
20   collection1   []  The period for a new election of a citizen to ...   
12   collection1   []  Fellow Citizens of the Senate and of the House...   
13   collection1   []  Whereas combinations to defeat the execution o...   
212  collection2   []  MR. PRESIDENT AND …