Question

filecontents = f.read()
from nltk.tokenize import sent_tokenize
sent_tokenize_list = sent_tokenize(filecontents)

for sentence in sent_tokenize_list:
    sentence = "Start " + sentence + " End"
    print sentence

结果如

"start ~~~~~~ end "
"start ~~~~~ end"
"start ~~~~~ end"

但我希望将它们全部连接起来，作为整个字符串。我该怎么做。

Answer 1

一个班轮：

" ".join(["Start " + sentence + " End" for sentence in sent_tokenize_list])

Answer 2

您可以将每个已处理的句子添加到结果中，例如

result = ''
for sentence in sent_tokenize_list:
    result += "Start " + sentence + " End"
print result

或者（并且以我认为的更加pythonic的方式）你可以使用list comprehension而不是for子句来制作修改后的句子列表，然后将所有句子加在一起

new_sentences = ['Start ' + sentence + ' End' for sentence in sent_tokenize_list]
result = ''.join(new_sentences)

Answer 3

您可以对空字符串使用列表推导和连接方法来连接所有句子。

print "".join(["Start " + sentence + " End" for sentence in sent_tokenize_list])

您还可以使用评论中提到的生成器理解来获得更好的性能。

print "".join("Start " + sentence + " End" for sentence in sent_tokenize_list)

Answer 4

尝试列表理解：

result = "".join("Start {} end".format(sentence) for sentence in sent_tokenize_list)

如何在“for clause”中连接字符串？

4 个答案: