从 difflib 获取更细粒度的差异（或 post 处理差异以实现相同目的的方法）

Question

正在下载 this 页面并对其进行小幅编辑，将本段中的第一个 65 更改为 68：

然后我用 BeauifulSoup 解析两个源，并用 difflib 对它们进行比较。

url = 'https://secure.ssa.gov/apps10/reference.nsf/links/02092016062645AM'
response = urllib2.urlopen(url)
content = response.read()  # get response as list of lines

url2 = 'file:///Users/Pyderman/projects/temp/02092016062645AM-modified.html'
response2 = urllib2.urlopen(url2)
content2 = response2.read()  # get response as list of lines
import difflib
d = difflib.Differ()

diffed = d.compare(content, content)

soup = bs4.BeautifulSoup(content, "lxml")
soup2= bs4.BeautifulSoup(content2, "lxml")
diff = d.compare(list(soup.stripped_strings), list(soup2.stripped_strings))
changes = [change for change in diff if change.startswith('-') or  change.startswith('+')]
for change in changes:
    print change

打印更改会得到：

- The Achieving a Better Life Experience (ABLE) Act, H.R. 5771, legislation passed on December 19, 2014. It contains a Title II provision that changes the age at which workers compensation/public disability offset ends for disability beneficiaries from age 65 to full retirement age (FRA).  This provision will apply to any individual who attains age 65 on or after December 19, 2015 (the one year anniversary of enactment of this bill).  Two new Universal Text Identifiers (UTIs), UTI WCP060 and WCP061 were created to comply with this change.
+ The Achieving a Better Life Experience (ABLE) Act, H.R. 5771, legislation passed on December 19, 2014. It contains a Title II provision that changes the age at which workers compensation/public disability offset ends for disability beneficiaries from age 68 to full retirement age (FRA).  This provision will apply to any individual who attains age 65 on or after December 19, 2015 (the one year anniversary of enactment of this bill).  Two new Universal Text Identifiers (UTIs), UTI WCP060 and WCP061 were created to comply with this change.

所以它正在打印整个段落，尽管有非常小的变化。我认为按整个段落而不是按句子显示差异是一件好事，但我们能否以某种方式使输出更精细？就目前而言，如果我想突出显示 只是更改的文本， 我将不得不对这两个几乎相同的字符串进行一些额外的增量比较。

Answer 1

您可以使用nltk.sent_tokenize()将汤字符串拆分成句子：

from nltk import sent_tokenize

sentences = [sentence for string in soup.stripped_strings for sentence in sent_tokenize(string)]
sentences2 = [sentence for string in soup2.stripped_strings for sentence in sent_tokenize(string)]

diff = d.compare(sentences, sentences2)
changes = [change for change in diff if change.startswith('-') or  change.startswith('+')]
for change in changes:
    print(change)

仅打印检测到更改的适当句子：

- It contains a Title II provision that changes the age at which workers compensation/public disability offset ends for disability beneficiaries from age 65 to full retirement age (FRA).
+ It contains a Title II provision that changes the age at which workers compensation/public disability offset ends for disability beneficiaries from age 68 to full retirement age (FRA).

从 difflib 获取更细粒度的差异（或 post 处理差异以实现相同目的的方法）

Getting more granular diffs from difflib (or a way to post-process a diff to achieve the same thing)

python

lxml

beautifulsoup

html-parsing

difflib