title: Parsing in python raises exception
body: <p>I used the below code to parse a server log in python using pyparsing and I was thrown an exception. It looks like the  grammar is correct as it works for one line of log but why do I see this exception? Thanks for any pointers or guidance!</p>
  
  <pre><code>#!/bin/python
  
  # import required modules
  # (include the ones used later after defining grammar)
  import string
  from pyparsing import alphas, nums, Combine, Word, Group, 
  delimitedList, Suppress, removeQuotes, alphanums
  
  test_data = """
  Oct 31 06:26:51 os-test-rb dhclient[844]: DHCPACK of 192.168.14.6 
  from 192.168.14.2
  """
  # define a function with the grammar
  
  logLine = None
  def getLog():
      global logLine
  
      if logLine is None:
          serverDateTime = Combine(Word(alphas) + Word(nums) + 
                            Word(nums) + ":" + Word(nums) + ":" + Word(nums))
          userName = Word(alphas+'-')
          clientName = Combine(Word(alphas) +"[" + Word(nums) + "]" + ":")
          message = Word(alphanums) + Word(alphas) + delimitedList( Word(nums), ".", combine=True ) + Word(alphas) + delimitedList( Word(nums), ".", combine=True )
  
          logLine = ( serverDateTime.setResultsName("timestamp") +
              userName.setResultsName("username") +
              clientName.setResultsName("client") +
              message.setResultsName("Message from Server"))
  
          return logLine
  
    # print out the log
  
  for line in test_data:
      if not line: continue
      data = getLog().parseString(line)
      print(data.dump())
      print(data.asXML("LOG"))
  </code></pre>
  
  <p>Exception raised is : </p>
  
  <pre><code>Traceback (most recent call last):
    File "server_log_parser1.py", line 63, in &lt;module&gt;
      data = getLog().parseString(line)
  
      raise ParseException(instring, loc, self.errmsg, self)
  pyparsing.ParseException: Expected W:(ABCD...) (at char 1), (line:2, col:1)
  </code></pre>