语料访问
语料访问详细操作教程
Corpora是一个展示多个文本文档集合的组。 单个集合称为语料库。 其中一个着名的语料库是古腾堡语料库，其中包含大约25,000本免费电子书，由
http://www.gutenberg.org/ 托管。 在下面的例子中，只访问语料库中那些文件的名称，这些文件是纯文本，以.txt结尾的文件名。
# Filename : example.py
# Copyright : 2020 By Lidihuo
# Author by : www.lidihuo.com
# Date : 2020-08-23
from nltk.corpus import gutenberg
fields = gutenberg.fileids()
print(fields)
执行上面示例代码，得到以下结果 -
# Filename : example.py
# Copyright : 2020 By Lidihuo
# Author by : www.lidihuo.com
# Date : 2020-08-23
[austen-emma.txt', austen-persuasion.txt', austen-sense.txt', bible-kjv.txt',
blake-poems.txt', bryant-stories.txt', burgess-busterbrown.txt',
carroll-alice.txt', chesterton-ball.txt', chesterton-brown.txt',
chesterton-thursday.txt', edgeworth-parents.txt', melville-moby_dick.txt',
milton-paradise.txt', shakespeare-caesar.txt', shakespeare-hamlet.txt',
shakespeare-macbeth.txt', whitman-leaves.txt']
访问原始文本
可以使用sent_tokenize函数从这些文件中访问原始文本，该函数也可以在nltk中使用。 在下面的例子中，将检索blake-poen文本的前两段。
# Filename : example.py
# Copyright : 2020 By Lidihuo
# Author by : www.lidihuo.com
# Date : 2020-08-23
from nltk.tokenize import sent_tokenize
from nltk.corpus import gutenberg
sample = gutenberg.raw("blake-poems.txt")
token = sent_tokenize(sample)
for para in range(2):
print(token[para])
当运行上面的程序时，我们得到以下输出 -
# Filename : example.py
# Copyright : 2020 By Lidihuo
# Author by : www.lidihuo.com
# Date : 2020-08-23
[Poems by William Blake 1789]
SONGS OF INNOCENCE and OF EXPERIENCE
and THE BOOK of THEL
SONGS OF INNOCENCE
INTRODUCTION
Piping down the valleys wild,
Piping songs of pleasant glee,
On a cloud I saw a child,
and he laughing said to me:
"Pipe a song about a Lamb!"
So I piped with merry cheer.
