python difflib 比较文件

Question

我正在尝试使用 difflib 为两个包含推文的文本文件生成 diff。这是代码：

#!/usr/bin/env python

# difflib_test

import difflib

file1 = open('/home/saad/Code/test/new_tweets', 'r')
file2 = open('/home/saad/PTITVProgs', 'r')

diff = difflib.context_diff(file1.readlines(), file2.readlines())
delta = ''.join(diff)
print delta

这是

PTITVProgs

文本文件：

Watch PTI on April 6th (7) Dr Israr Shah at 10PM on Business Plus in "Talking Policy". Rgds #PTI
CORRECTION!! Watch PTI on April 6th (5) @Asad_Umar  at 8PM on ARY News. Rgds #PTI
Watch PTI on April 6th (5) @Asad_Umar  at 8PM on AAJ News (6) PTI vs PMLN at 8PM on NewsOne. Rgds #PTI
Watch PTI on April 6th (5) Asad Umar at 8PM on AAJ News (6) PTI vs PMLN at 8PM on NewsOne. Rgds #PTI
Watch PTI on April 6th (5) Waleed Iqbal at 8PM on Channel 5. Rgds #PTI
Watch PTI on April 6th (3) Dr Israr Shah at 10PM on PTV News. Rgds #PTI
Watch PTI on April 6th (4) Javed hashmi at 1PM on PTV News. Rgds #PTI
Watch PTI on April 6th (3) Imran Alvi at 1PM on AAJ News. Rgds #PTI
Watch PTI on April 6th (1) Dr @ArifAlvi, Andleeb Abbas and Ehtisham Ameer at 11PM on ARY News (2) Hamid Khan at 10PM on ATV. Rgds #PTI
Watch PTI on April 5th (1) Farooq Amjad Meer at 10:45PM on Dunya News. Rgds #PTI
Watch PTI on April 4th (4) Faisal Khan at 8PM on PTV News. Rgds #PTI
@FaisalJavedKhan
Watch PTI on April 4th (3) Faisal Khan at 11PM on ATV. Rgds #PTI
@FaisalJavedKhan
Watch PTI on April 4th (1) Dr Israr Shah at 8PM on Waqt News (2) Dr Arif Alvi at 9PM on PTV World. Rgds #PTI
@ArifAlvi
Watch PTI on April 3rd (12) Abrar ul Haq on 10PM on Dawn News (13) Shabbir Sial at 10PM on Channel5. Rgds #PTI
Watch PTI on April 3rd (11) Sadaqat Abbasi on 8PM on RohiTV. Rgds #PTI
Watch PTI on April 3rd (10) Dr Zarqa and Andleeb Abbas on 8PM on Waqt News. Rgds #PTI
Watch PTI on April 3rd (9) Fauzia Kasuri at 8PM on Din News. Rgds #PTI
Watch PTI on April 3rd (8) Mehmood Rasheed at 8PM on ARY News. Rgds #PTI
Watch PTI on April 3rd (7) Israr Abbasi (Repeat on Arp 4th) at 1:20AM and 1PM on Vibe TV. Rgds #PTI
Watch PTI on April 3rd (5) Rao Fahad at 9PM on Express News (6) Dr Seems Zia at 10:30PM on Health TV. Rgds #PTI

这是

new_tweets

文本文件：

Watch PTI on April 7th (3) Malaika Reza at 8PM on AAJ News (4) Shah Mehmood Qureshi at 8PM on Geo News. Rgds #PTI
Watch PTI on April 7th (2) Chairman IMRAN KHAN at 10PM on PTV News in News Night with Sadia Afzal, Rpt: 2AM, 2PM. Rgds #PTI
@ImranKhanPTI
Watch PTI on April 7th (1) Dr Waseem Shahzad NOW at 6PM on PTV News. Rgds #PTI
Watch PTI on April 6th (7) Dr Israr Shah at 10PM on Business Plus in "Talking Policy". Rgds #PTI
CORRECTION!! Watch PTI on April 6th (5) @Asad_Umar  at 8PM on ARY News. Rgds #PTI
Watch PTI on April 6th (5) @Asad_Umar  at 8PM on AAJ News (6) PTI vs PMLN at 8PM on NewsOne. Rgds #PTI
Watch PTI on April 6th (5) Asad Umar at 8PM on AAJ News (6) PTI vs PMLN at 8PM on NewsOne. Rgds #PTI
Watch PTI on April 6th (5) Waleed Iqbal at 8PM on Channel 5. Rgds #PTI
Watch PTI on April 6th (3) Dr Israr Shah at 10PM on PTV News. Rgds #PTI
Watch PTI on April 6th (4) Javed hashmi at 1PM on PTV News. Rgds #PTI
Watch PTI on April 6th (3) Imran Alvi at 1PM on AAJ News. Rgds #PTI
Watch PTI on April 6th (1) Dr @ArifAlvi, Andleeb Abbas and Ehtisham Ameer at 11PM on ARY News (2) Hamid Khan at 10PM on ATV. Rgds #PTI
Watch PTI on April 5th (1) Farooq Amjad Meer at 10:45PM on Dunya News. Rgds #PTI
Watch PTI on April 4th (4) Faisal Khan at 8PM on PTV News. Rgds #PTI
@FaisalJavedKhan
Watch PTI on April 4th (3) Faisal Khan at 11PM on ATV. Rgds #PTI
@FaisalJavedKhan
Watch PTI on April 4th (1) Dr Israr Shah at 8PM on Waqt News (2) Dr Arif Alvi at 9PM on PTV World. Rgds #PTI
@ArifAlvi
Watch PTI on April 3rd (12) Abrar ul Haq on 10PM on Dawn News (13) Shabbir Sial at 10PM on Channel5. Rgds #PTI
Watch PTI on April 3rd (11) Sadaqat Abbasi on 8PM on RohiTV. Rgds #PTI
Watch PTI on April 3rd (10) Dr Zarqa and Andleeb Abbas on 8PM on Waqt News. Rgds #PTI
Watch PTI on April 3rd (9) Fauzia Kasuri at 8PM on Din News. Rgds #PTI

这是我从程序中得到的差异：

*** 
--- 
***************
*** 1,7 ****
- Watch PTI on April 7th (3) Malaika Reza at 8PM on AAJ News (4) Shah Mehmood Qureshi at 8PM on Geo News. Rgds #PTI
- Watch PTI on April 7th (2) Chairman IMRAN KHAN at 10PM on PTV News in News Night with Sadia Afzal, Rpt: 2AM, 2PM. Rgds #PTI
- @ImranKhanPTI
- Watch PTI on April 7th (1) Dr Waseem Shahzad NOW at 6PM on PTV News. Rgds #PTI
  Watch PTI on April 6th (7) Dr Israr Shah at 10PM on Business Plus in "Talking Policy". Rgds #PTI
  CORRECTION!! Watch PTI on April 6th (5) @Asad_Umar  at 8PM on ARY News. Rgds #PTI
  Watch PTI on April 6th (5) @Asad_Umar  at 8PM on AAJ News (6) PTI vs PMLN at 8PM on NewsOne. Rgds #PTI
--- 1,3 ----
***************
*** 21,24 ****
  Watch PTI on April 3rd (12) Abrar ul Haq on 10PM on Dawn News (13) Shabbir Sial at 10PM on Channel5. Rgds #PTI
  Watch PTI on April 3rd (11) Sadaqat Abbasi on 8PM on RohiTV. Rgds #PTI
  Watch PTI on April 3rd (10) Dr Zarqa and Andleeb Abbas on 8PM on Waqt News. Rgds #PTI
! Watch PTI on April 3rd (9) Fauzia Kasuri at 8PM on Din News. Rgds #PTI--- 17,23 ----
  Watch PTI on April 3rd (12) Abrar ul Haq on 10PM on Dawn News (13) Shabbir Sial at 10PM on Channel5. Rgds #PTI
  Watch PTI on April 3rd (11) Sadaqat Abbasi on 8PM on RohiTV. Rgds #PTI
  Watch PTI on April 3rd (10) Dr Zarqa and Andleeb Abbas on 8PM on Waqt News. Rgds #PTI
! Watch PTI on April 3rd (9) Fauzia Kasuri at 8PM on Din News. Rgds #PTI
! Watch PTI on April 3rd (8) Mehmood Rasheed at 8PM on ARY News. Rgds #PTI
! Watch PTI on April 3rd (7) Israr Abbasi (Repeat on Arp 4th) at 1:20AM and 1PM on Vibe TV. Rgds #PTI
! Watch PTI on April 3rd (5) Rao Fahad at 9PM on Express News (6) Dr Seems Zia at 10:30PM on Health TV. Rgds #PTI

通过快速比较两个源文件（PTITVProgs 和 new_tweets）您可以看到，它们之间的差异是 4 月 7 日的 3 条推文和 4 月 3 日的 3 条推文。

我只想让

new_tweets

中不在

PTITVProgs

中的行出现在差异中。

但是它抛出了一堆我不想看到的文本。我不知道 diff 输出中的

*** 1,7***

和

*** 1,3***

代表什么......？ 仅更改的行的正确方法是什么？

Answer 1

只需像这样解析 diff 的输出（如果需要，将“-”更改为“+”）：

#!/usr/bin/env python

# difflib_test

import difflib

file1 = open('/home/saad/Code/test/new_tweets', 'r')
file2 = open('/home/saad/PTITVProgs', 'r')

diff = difflib.ndiff(file1.readlines(), file2.readlines())
delta = ''.join(x[2:] for x in diff if x.startswith('- '))
print delta

Answer 2

difflib

库中有多种 diff 样式和不同的功能。

unified_diff

、

ndiff

和

context_diff

。

如果您不需要行号摘要，

ndiff

函数会提供不同样式的增量：

import difflib

f1 = '''1
2
3
4
5'''
f2 = '''1
3
4
5
6'''

diff = difflib.ndiff(f1,f2)

for l in diff:
    print(l)

输出：

  1
- 2          
  3          
  4          
  5   
+ 6

编辑：

如果您想要的话，您还可以解析差异以仅提取更改：

>>>changes = [l for l in diff if l.startswith('+ ') or l.startswith('- ')]

>>>for c in changes:
       print(c)
>>>
- 2
+ 6

Answer 3

Python 中用于比较文件和突出显示差异的最佳工具之一是 Google 的 diff-match-patch 库。

让我们看看您的示例。

PTITVProgs = """Watch PTI on April 6th (7) Dr Israr Shah at 10PM on Business Plus in "Talking Policy". Rgds #PTI
CORRECTION!! Watch PTI on April 6th (5) @Asad_Umar  at 8PM on ARY News. Rgds #PTI
Watch PTI on April 6th (5) @Asad_Umar  at 8PM on AAJ News (6) PTI vs PMLN at 8PM on NewsOne. Rgds #PTI
Watch PTI on April 6th (5) Asad Umar at 8PM on AAJ News (6) PTI vs PMLN at 8PM on NewsOne. Rgds #PTI
Watch PTI on April 6th (5) Waleed Iqbal at 8PM on Channel 5. Rgds #PTI
Watch PTI on April 6th (3) Dr Israr Shah at 10PM on PTV News. Rgds #PTI
Watch PTI on April 6th (4) Javed hashmi at 1PM on PTV News. Rgds #PTI
Watch PTI on April 6th (3) Imran Alvi at 1PM on AAJ News. Rgds #PTI
Watch PTI on April 6th (1) Dr @ArifAlvi, Andleeb Abbas and Ehtisham Ameer at 11PM on ARY News (2) Hamid Khan at 10PM on ATV. Rgds #PTI
Watch PTI on April 5th (1) Farooq Amjad Meer at 10:45PM on Dunya News. Rgds #PTI
Watch PTI on April 4th (4) Faisal Khan at 8PM on PTV News. Rgds #PTI
@FaisalJavedKhan
Watch PTI on April 4th (3) Faisal Khan at 11PM on ATV. Rgds #PTI
@FaisalJavedKhan
Watch PTI on April 4th (1) Dr Israr Shah at 8PM on Waqt News (2) Dr Arif Alvi at 9PM on PTV World. Rgds #PTI
@ArifAlvi
Watch PTI on April 3rd (12) Abrar ul Haq on 10PM on Dawn News (13) Shabbir Sial at 10PM on Channel5. Rgds #PTI
Watch PTI on April 3rd (11) Sadaqat Abbasi on 8PM on RohiTV. Rgds #PTI
Watch PTI on April 3rd (10) Dr Zarqa and Andleeb Abbas on 8PM on Waqt News. Rgds #PTI
Watch PTI on April 3rd (9) Fauzia Kasuri at 8PM on Din News. Rgds #PTI
Watch PTI on April 3rd (8) Mehmood Rasheed at 8PM on ARY News. Rgds #PTI
Watch PTI on April 3rd (7) Israr Abbasi (Repeat on Arp 4th) at 1:20AM and 1PM on Vibe TV. Rgds #PTI
Watch PTI on April 3rd (5) Rao Fahad at 9PM on Express News (6) Dr Seems Zia at 10:30PM on Health TV. Rgds #PTI"""

new_tweets = """Watch PTI on April 7th (3) Malaika Reza at 8PM on AAJ News (4) Shah Mehmood Qureshi at 8PM on Geo News. Rgds #PTI
Watch PTI on April 7th (2) Chairman IMRAN KHAN at 10PM on PTV News in News Night with Sadia Afzal, Rpt: 2AM, 2PM. Rgds #PTI
@ImranKhanPTI
Watch PTI on April 7th (1) Dr Waseem Shahzad NOW at 6PM on PTV News. Rgds #PTI
Watch PTI on April 6th (7) Dr Israr Shah at 10PM on Business Plus in "Talking Policy". Rgds #PTI
CORRECTION!! Watch PTI on April 6th (5) @Asad_Umar  at 8PM on ARY News. Rgds #PTI
Watch PTI on April 6th (5) @Asad_Umar  at 8PM on AAJ News (6) PTI vs PMLN at 8PM on NewsOne. Rgds #PTI
Watch PTI on April 6th (5) Asad Umar at 8PM on AAJ News (6) PTI vs PMLN at 8PM on NewsOne. Rgds #PTI
Watch PTI on April 6th (5) Waleed Iqbal at 8PM on Channel 5. Rgds #PTI
Watch PTI on April 6th (3) Dr Israr Shah at 10PM on PTV News. Rgds #PTI
Watch PTI on April 6th (4) Javed hashmi at 1PM on PTV News. Rgds #PTI
Watch PTI on April 6th (3) Imran Alvi at 1PM on AAJ News. Rgds #PTI
Watch PTI on April 6th (1) Dr @ArifAlvi, Andleeb Abbas and Ehtisham Ameer at 11PM on ARY News (2) Hamid Khan at 10PM on ATV. Rgds #PTI
Watch PTI on April 5th (1) Farooq Amjad Meer at 10:45PM on Dunya News. Rgds #PTI
Watch PTI on April 4th (4) Faisal Khan at 8PM on PTV News. Rgds #PTI
@FaisalJavedKhan
Watch PTI on April 4th (3) Faisal Khan at 11PM on ATV. Rgds #PTI
@FaisalJavedKhan
Watch PTI on April 4th (1) Dr Israr Shah at 8PM on Waqt News (2) Dr Arif Alvi at 9PM on PTV World. Rgds #PTI
@ArifAlvi
Watch PTI on April 3rd (12) Abrar ul Haq on 10PM on Dawn News (13) Shabbir Sial at 10PM on Channel5. Rgds #PTI
Watch PTI on April 3rd (11) Sadaqat Abbasi on 8PM on RohiTV. Rgds #PTI
Watch PTI on April 3rd (10) Dr Zarqa and Andleeb Abbas on 8PM on Waqt News. Rgds #PTI
Watch PTI on April 3rd (9) Fauzia Kasuri at 8PM on Din News. Rgds #PTI"""

寻找差异

import diff_match_patch as dmp_module    # !pip install diff-match-patch
dmp = dmp_module.diff_match_patch()
diff = dmp.diff_main(PTITVProgs, new_tweets)
dmp.diff_cleanupSemantic(diff)
# diff
# [(1,
#   'Watch PTI on April 7th (3) Malaika Reza at 8PM on AAJ News (4) Shah Mehmood Qureshi at 8PM on Geo News. Rgds #PTI\nWatch PTI on April 7th (2) Chairman IMRAN KHAN at 10PM on PTV News in News Night with Sadia Afzal, Rpt: 2AM, 2PM. Rgds #PTI\n@ImranKhanPTI\nWatch PTI on April 7th (1) Dr Waseem Shahzad NOW at 6PM on PTV News. Rgds #PTI\n'),
#  (0,
#   'Watch PTI on April 6th (7) Dr Israr Shah at 10PM on Business Plus in "Talking Policy". Rgds #PTI\nCORRECTION!! Watch PTI on April 6th (5) @Asad_Umar  at 8PM on ARY News. Rgds #PTI\nWatch PTI on April 6th (5) @Asad_Umar  at 8PM on AAJ News (6) PTI vs PMLN at 8PM on NewsOne. Rgds #PTI\nWatch PTI on April 6th (5) Asad Umar at 8PM on AAJ News (6) PTI vs PMLN at 8PM on NewsOne. Rgds #PTI\nWatch PTI on April 6th (5) Waleed Iqbal at 8PM on Channel 5. Rgds #PTI\nWatch PTI on April 6th (3) Dr Israr Shah at 10PM on PTV News. Rgds #PTI\nWatch PTI on April 6th (4) Javed hashmi at 1PM on PTV News. Rgds #PTI\nWatch PTI on April 6th (3) Imran Alvi at 1PM on AAJ News. Rgds #PTI\nWatch PTI on April 6th (1) Dr @ArifAlvi, Andleeb Abbas and Ehtisham Ameer at 11PM on ARY News (2) Hamid Khan at 10PM on ATV. Rgds #PTI\nWatch PTI on April 5th (1) Farooq Amjad Meer at 10:45PM on Dunya News. Rgds #PTI\nWatch PTI on April 4th (4) Faisal Khan at 8PM on PTV News. Rgds #PTI\n@FaisalJavedKhan\nWatch PTI on April 4th (3) Faisal Khan at 11PM on ATV. Rgds #PTI\n@FaisalJavedKhan\nWatch PTI on April 4th (1) Dr Israr Shah at 8PM on Waqt News (2) Dr Arif Alvi at 9PM on PTV World. Rgds #PTI\n@ArifAlvi\nWatch PTI on April 3rd (12) Abrar ul Haq on 10PM on Dawn News (13) Shabbir Sial at 10PM on Channel5. Rgds #PTI\nWatch PTI on April 3rd (11) Sadaqat Abbasi on 8PM on RohiTV. Rgds #PTI\nWatch PTI on April 3rd (10) Dr Zarqa and Andleeb Abbas on 8PM on Waqt News. Rgds #PTI\nWatch PTI on April 3rd (9) Fauzia Kasuri at 8PM on Din News. Rgds #PTI'),
#  (-1,
#   '\nWatch PTI on April 3rd (8) Mehmood Rasheed at 8PM on ARY News. Rgds #PTI\nWatch PTI on April 3rd (7) Israr Abbasi (Repeat on Arp 4th) at 1:20AM and 1PM on Vibe TV. Rgds #PTI\nWatch PTI on April 3rd (5) Rao Fahad at 9PM on Express News (6) Dr Seems Zia at 10:30PM on Health TV. Rgds #PTI')]

在输出列表

diff

中，第一个变量是0/1/-1，第二个变量是文本。 0 表示文本是通用的，1 表示在第二个文件中添加文本，-1 表示从第一个文件中删除文本。因此，要查看

new_tweets

中不在

PTITVProgs

中的行：

for change,text in diff:
    if change==1:
        print(text)
# Watch PTI on April 7th (3) Malaika Reza at 8PM on AAJ News (4) Shah Mehmood Qureshi at 8PM on Geo News. Rgds #PTI
# Watch PTI on April 7th (2) Chairman IMRAN KHAN at 10PM on PTV News in News Night with Sadia Afzal, Rpt: 2AM, 2PM. Rgds #PTI
# @ImranKhanPTI
# Watch PTI on April 7th (1) Dr Waseem Shahzad NOW at 6PM on PTV News. Rgds #PTI

请注意，即使线条部分不同，它也能正常工作。

但是，我通过可视化 HTML 的差异来使用它：

html = dmp.diff_prettyHtml(diff)
html = html.replace('¶', '')    # Not displaying newline characters. Newline differences won't appear.

# Display it in Jupyter
from IPython.core.display import display, HTML
display(HTML(html))

第一个文件中的红色删除线已删除，第二个文件中添加了绿色下划线。