title: How to avoid division by zero error, when performing calculations on parsed xml data
body: <p>please be kind with your answers I have been coding now for 10 days. I am having trouble with performing loops in my code, but I am fairly certain this is because I am getting a traceback. </p>
  
  <p>I parse an xml file obtained from a url, using the following code: </p>
  
  <pre><code>pattern4 = re.compile('title=\'Naps posted: (.*) Winners:')
  pattern5 = re.compile('Winners: (.*)\'&gt;&lt;img src=')
  
  for row in xmlload1['rows']:
      cell = row["cell"]
  
  ##### defining the Keys (key is the area from which data is pulled in the XML) for use   in the pattern finding/regex
      user_delimiter = cell['username']
      selection_delimiter = cell['race_horse']
  
  ##### the use of the float here is to make sure the result of the strike rate calculations returns as a decimal, otherwise python 2 rounds to the nearest integer! 
      user_numberofselections = float(re.findall(pattern4, user_delimiter)[0])
      user_numberofwinners = float(re.findall(pattern5, user_delimiter)[0])
  
      strikeratecalc1 = user_numberofwinners/user_numberofselections
      strikeratecalc2 = strikeratecalc1*100
  
  ##### Printing the results of the code at hand
  
      print "number of selections = ",user_numberofselections
      print "number of winners = ",user_numberofwinners
      print "Strike rate = ",strikeratecalc2,"%"
      print ""
  
  getData()
  </code></pre>
  
  <p>This code with the rest of the code returns: </p>
  
  <pre><code>number of selections =  112.0
  number of winners =  21.0
  Strike rate =  18.75 %
  
  number of selections =  146.0
  number of winners =  21.0
  Strike rate =  14.3835616438 %
  
  number of selections =  163.0
  number of winners =  55.0
  Strike rate =  33.7423312883 %
  </code></pre>
  
  <p>Now the results of this xmlload suggest that there is only three users to parse however there is a 4th whos data would read </p>
  
  <pre><code>number of selections =  0
  number of winners =  0
  Strike rate =  0
  </code></pre>
  
  <p>for my purposes it is not necessary to pull in user stat's for those with no track record, how do i make the code either skip users with 0 selections or at least make it so that the division by zero error doesn't affect the ability of the code to run in a loop?</p>
  
  <p>Kind regards! </p>