title: How to find overlapping rows between two dataframes based on start and end columns?
body: <p>I have two pandas dataframes df1 and df2 of the form:</p>
  <p><strong>df1</strong></p>
  <pre><code>start   end   text   source
  1       5     abc     1  
  8       10    def     1
  15      20    ghi     1
  25      30    xxx     1
  42      45    zzz     1 
  </code></pre>
  <p><strong>df2</strong></p>
  <pre><code>start   end   text   source
  1       6     jkl     2  
  7       9     mno     2
  11      13    pqr     2
  16      17    stu     2
  18      19    vwx     2
  32      37    yyy     2
  40      47    rrr     2
  </code></pre>
  <p>I want to return the intersections of the two dataframes based on the start and end columns in following format:</p>
  <p><strong>out_df</strong></p>
  <pre><code>start_1   end_1   start_2   end_2  text_1   text_2
  1         5       1         6      abc      jkl        
  8         10      7         9      def      mno
  15        20      16        17     ghi      stu 
  15        20      18        19     ghi      vwx
  42        45      40        47     zzz      rrr
  </code></pre>
  <p>What is the best method to achieve this?</p>