title: Merging rows together on condition
body: <p>I have data that looks like this</p>
  <pre><code>import pandas as pd
  current_df = pd.DataFrame({ 'Col1':['Something (Something', 'Else) words', 'x', 'y', 'something (another', 'word) blah'], 
                      'Col2':['(some value)', '', 'some value', 'a', 'some value',''],
                      'Col3':['Something (Something', 'Else) words', '(x)', 'y', 'something (another', 'word) blah'], 
                      'Col4':['some value', '', 'some value', 'a', 'some value',''],
                      'Col5':['some value', '', 'some value', 'a', 'some value','']})
  
                     Col1          Col2                  Col3        Col4        Col5
  0  Something (Something  (some value)  Something (Something  some value  some value
  1           Else) words                         Else) words
  2                     x    some value                   (x)  some value  some value
  3                     y             a                     y           a           a
  4    something (another    some value    something (another  some value  some value
  5            word) blah  
  
  </code></pre>
  <p>I scraped this from a PDF and in some cases, there was a weird formatting issue where something would carry over to another line.  It is always in the same two columns, and there is nothing else in those columns, just as I have shown.  Is there a way that I could merge those values with the row above?  Desired output is below.</p>
  <p>In the example, the data I want to join is split by ( in one row and ) in the next.  This is true for about 99% of my data, and I was thinking about trying to leverage that.  But if there is a cleaner way to just merge the cells up, please let me know.</p>
  <pre><code>goal_df = pd.DataFrame({ 'Col1':['Something (Something Else) words', 'x', 'y', 'something (another word) blah'], 
                      'Col2':['(some value)', 'some value', 'a', 'some value'],
                      'Col3':['Something (Something Else) words', '(x)', 'y', 'something (another word) blah'], 
                      'Col4':['some value', 'some value', 'a', 'some value'],
                      'Col5':['some value', 'some value', 'a', 'some value'],})
  
                                 Col1          Col2                              Col3        Col4        Col5
  0  Something (Something Else) words  (some value)  Something (Something Else) words  some value  some value
  1                                 x    some value                               (x)  some value  some value
  2                                 y             a                                 y           a           a
  3     something (another word) blah    some value     something (another word) blah  some value  some value
  
  </code></pre>