title: How to read the csv file properly if each row contains different number of fields (number quite big)?
body: <p>I have a text file from amazon, containing the following info:</p>
  
  <pre><code> #      user        item     time   rating     review text (the header is added by me for explanation, not in the text file
    disjiad123    TYh23hs9     13160032    5     I love this phone as it is easy to use
    hjf2329ccc    TGjsk123     14423321    3     Suck restaurant
  </code></pre>
  
  <p>As you see, the data is separated by space and there are different number of columns in each row. However, so it is the text content. 
  Here is the code I have tried:</p>
  
  <pre><code>pd.read_csv(filename, sep = " ", header = None, names = ["user","item","time","rating", "review"], usecols = ["user", "item", "rating"])#I'd like to skip the text review part
  </code></pre>
  
  <p>And such an error occurs:</p>
  
  <pre><code>ValueError: Passed header names mismatches usecols
  </code></pre>
  
  <p>When I tried to read all the columns:</p>
  
  <pre><code>pd.read_csv(filename, sep = " ", header = None)
  </code></pre>
  
  <p>And the error this time is:</p>
  
  <pre><code>Error tokenizing data. C error: Expected 229 fields in line 3, saw 320
  </code></pre>
  
  <p>And given the review text is so long in many rows , the method of adding header names for each column in this <a href="https://stackoverflow.com/questions/27020216/import-csv-with-different-number-of-columns-per-row-using-pandas">question</a> can not work. </p>
  
  <p>I wonder how to read the csv file if I want to keep the review text and skip them respectively. Thank you in advance! </p>
  
  <p>EDIT:</p>
  
  <p>The problem has been solved by Martin Evans perfectly. But now I am playing with another data set with similar but different format. Now the order of the data is converse:</p>
  
  <pre><code>     # review text                          user        item     time   rating      (the header is added by me for explanation, not in the text file
     I love this phone as it is easy to used  isjiad123    TYh23hs9     13160032    5    
    Suck restaurant                           hjf2329ccc    TGjsk123     14423321    3     
  </code></pre>
  
  <p>Do you have any idea to read it properly? It would be appreciated for any help!</p>