title: Why does csv.DictReader skip empty lines?
body: <p>It seems that <code>csv.DictReader</code> skips empty lines, even when <code>restval</code> is set. Using the following, empty lines in the input file are skipped:</p>
  
  <pre><code>import csv
  CSV_FIELDS = ("field1", "field2", "field3")
  for row in csv.DictReader(open("f"), fieldnames=CSV_FIELDS, restval=""):
      if not row or not row[CSV_FIELDS[0]]:
          sys.exit("never reached, why?")
  </code></pre>
  
  <p>Where file <code>f</code> is:</p>
  
  <pre><code>1,2,3
  
  
  a,b,c
  </code></pre>