title: starting tshark with python - invalid command
body: <p>I'm trying to start tshark with python. Testing the command in command line seems to be OK. but while starting it with python, I'm getting error as described below.</p>
  <p>Any idea what is going wrong?</p>
  <pre><code>cmd1='&quot;tshark -i 1 -Y &quot;ssdp&quot; -T fields -E separator=, -E header=y -e ip.id -e ip.checksum&quot;'
  cmd=shlex.split(cmd1)
  
  try:
      tsharkProc = subprocess.Popen(cmd,
                                    shell=True,
                                    stdout=subprocess.PIPE,
                                    executable=&quot;C:\\Program Files\\Wireshark\\tshark.exe&quot;)
  except:
      print(&quot;ERROR {} while running {}&quot;.format(sys.exc_info()[1], cmd))
  </code></pre>
  <p>And the error:</p>
  <blockquote>
  <p>Capturing on 'Ethernet 2' tshark: Invalid capture filter &quot;/c tshark -i
  1 -Y ssdp -T fields -E separator=, -E header=y -e ip.id -e
  ip.checksum&quot; for interface 'Ethernet 2'.</p>
  <p>That string isn't a valid capture filter (can't parse filter
  expression: syntax error). See the User's Guide for a description of
  the capture filter syntax. 0 packets captured</p>
  </blockquote>