python - 如何将 Reuters-21578 数据集作为 Python 中标记化功能的输入参数传递

Question

我尝试将 Reuters-21578 数据集作为输入参数传递给 tokenize funktion def tokenize(text):，它应该删除停用词、标记化、词干和小写。

#!/usr/bin/python3
import nltk
import pandas as pd
import numpy as np
import string
from nltk.corpus import reuters
from nltk import word_tokenize
from nltk.stem.porter import PorterStemmer
from nltk.corpus import stopwords
import re
cachedStopWords = stopwords.words("english")


 for index, i in  enumerate(reuters.fileids()):
    text = reuters.raw(fileids=[i])

    #output in a txt file
#print(text, file=open("output.txt", "a"))


def tokenize(text):
    min_length = 3
    words = map(lambda word: word.lower(), word_tokenize(text));
    words = [word for word in words
                  if word not in cachedStopWords]
    tokens =(list(map(lambda token: PorterStemmer().stem(token),
                  words)));
    p = re.compile('[a-zA-Z]+');
    filtered_tokens =list(filter(lambda token:
                  p.match(token) and len(token)>=min_length,
         tokens));
    return filtered_tokens

result=tokenize(text)
print(result)

结果，我只得到以下信息：

['a.h.a', 'automot', 'technolog', 'corp', 'year', 'net', 'shr', 'shr', 'dilut', 'net', 'rev', 'mln', 'mln']

如果我将整个数据集传递给 tokenize 函数，那怎么可能呢？

Answer 1

您正在为每个 for 循环覆盖文本，这就是为什么您要获得属于路透社数据集中最后一条记录的输出。只需对您的代码进行小修改..

text = ''
for index, i in  enumerate(reuters.fileids()):
    text += reuters.raw(fileids=[i])