Question

我正在尝试使用新的词干字符串值重新分配该系列中列表的值。但是，我不知道该怎么做。目前，我正在制作一个新列表，并附加新词干，但这只是将所有列表中的所有单词放到列表ns中。我只想在其中使用新词干更新当前列表的地方。

words = data.String.apply(lambda x: word_tokenize(x))
ns =[]
#print(words)
for i in words:
    for j in i:
        ns.append(ps.stem(j))

例如，words =

0    [I, loved, dogs, because, they, are, cute, and...
1    [my, dog, is, looking, at, me, weird, maybe, c...
2    [I, think, I, look, like, a, cupacake, one, wi...
3    [do, you, want, to, be, a, snowman, no, thanks...
4    [hey, do, you, know, what, time, it, is, cooking,...
5     [dogs, are, so, awesome, dogs, are, so, awesome]

在通过for循环插入单词之后，words应该像这样：

    0    [I, love, dog, becaus, they, are, cute, and...
    1    [my, dog, is, look, at, me, weird, maybe, c...
    2    [I, think, I, look, like, a, cupacake, one, wi...
    3    [do, you, want, to, be, a, snowman, no, thank...
    4    [hey, do, you, know, what, time, it, is, cook,...
    5     [dog, are, so, awesome, dog, are, so, awesome]

在：

print(type(words))
print(type(words[1]))
print(type(words[1][1]))

出局：

<class 'pandas.core.series.Series'>
<class 'list'>
<class 'str'>

有什么想法吗？

谢谢！

Answer 1

将列表理解与ps.stem函数一起使用：

print (data)
                                    String
0   I loved dogs because they are cute and
1      my dog is looking at me weird maybe
2       I think I look like a cupacake one
3    do you want to be a snowman no thanks
4  hey do you know what time it is cooking
5  dogs are so awesome dogs are so awesome

from nltk.stem.snowball import SnowballStemmer
from nltk import word_tokenize
ps = SnowballStemmer("english")

words = data.String.apply(lambda x: [ps.stem(y) for y in word_tokenize(x)])
print (words)
0      [i, love, dog, becaus, they, are, cute, and]
1          [my, dog, is, look, at, me, weird, mayb]
2        [i, think, i, look, like, a, cupacak, one]
3    [do, you, want, to, be, a, snowman, no, thank]
4    [hey, do, you, know, what, time, it, is, cook]
5      [dog, are, so, awesom, dog, are, so, awesom]
Name: String, dtype: object

如果需要重新分配到同一列：

data.String = data.String.apply(lambda x: [ps.stem(y) for y in word_tokenize(x)])
print (data)
                                           String
0    [i, love, dog, becaus, they, are, cute, and]
1        [my, dog, is, look, at, me, weird, mayb]
2      [i, think, i, look, like, a, cupacak, one]
3  [do, you, want, to, be, a, snowman, no, thank]
4  [hey, do, you, know, what, time, it, is, cook]
5    [dog, are, so, awesom, dog, are, so, awesom]

或转到新列：

data['Stem'] = data.String.apply(lambda x: [ps.stem(y) for y in word_tokenize(x)])

Answer 2

如果要保留两个for循环，则需要使用索引进行浏览。在python中，当您使用for i in lst时。 i等于列表中的每个元素。要更改列表中的值，您将需要索引。

更改循环以使用索引代替：

for i in range(len(words)):
    for j in range(len(words[i])):
       words[i][j] = "something new"

这将允许您更改数组中[i][j]点的值。

在一系列列表中重新分配字符串值

2 个答案: