title: python difflib comparing files
body: <p>I am trying to use difflib to produce diff for two text files containing tweets. Here is the code:</p>
  
  <pre><code>#!/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
  </code></pre>
  
  <p>Here is the <code>PTITVProgs</code> text file:</p>
  
  <pre><code>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
  </code></pre>
  
  <p>Here is the <code>new_tweets</code> text file: </p>
  
  <pre><code>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
  </code></pre>
  
  <p>Here is the diff i get from the program:</p>
  
  <pre><code>*** 
  --- 
  ***************
  *** 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
  </code></pre>
  
  <p>As you can see by quickly comparing the two source files (PTITVProgs and new_tweets) that the difference between them are <strong>the 3 tweets that were on April 7th</strong> and <strong>3 tweets on April 3rd</strong>. </p>
  
  <p>I just want the lines in <code>new_tweets</code> that are not in <code>PTITVProgs</code> to appear in the diff. </p>
  
  <p>But it throws a bunch of text that I don't want to see. I don't know what <code>*** 1,7***</code> and <code>*** 1,3***</code> in the diff output stand for...? What is the proper way to get <strong>only</strong> the changed lines?</p>