title: TypeError: can only concatenate list (not "int") to list
body: <p>I'm trying to do something usefull with some itens in list in the following code:</p>
  
  <pre><code>IPS=['10.254.243.83','10.254.243.82']
  
  def commands(cmd):
      command = Popen(cmd, shell=True, stdout=PIPE)
      command_strip = command.stdout.read().strip()
      print command_strip
  
  def main():
      for ip in IPS:
          ping = call('ping -c 3 %s' % ip, shell=True)
          commands(ping)
  
  if __name__ == "__main__":
      main()
  </code></pre>
  
  <p>Then, it returns me:
  python teste.py</p>
  
  <pre><code>PING 10.254.243.83 (10.254.243.83) 56(84) bytes of data.
  64 bytes from 10.254.243.83: icmp_seq=1 ttl=61 time=2.72 ms
  64 bytes from 10.254.243.83: icmp_seq=2 ttl=61 time=2.05 ms
  64 bytes from 10.254.243.83: icmp_seq=3 ttl=61 time=1.88 ms
  
  --- 10.254.243.83 ping statistics ---
  3 packets transmitted, 3 received, 0% packet loss, time 2004ms
  rtt min/avg/max/mdev = 1.885/2.224/2.728/0.363 ms
  
  Traceback (most recent call last):
    File "teste.py", line 15, in ?
      main()
    File "teste.py", line 12, in main
      commands(ping)
    File "teste.py", line 5, in commands
      command = Popen(cmd, shell=True, stdout=PIPE)
    File "/usr/lib/python2.4/subprocess.py", line 543, in __init__
      errread, errwrite)
    File "/usr/lib/python2.4/subprocess.py", line 891, in _execute_child
      args = ["/bin/sh", "-c"] + args
  TypeError: can only concatenate list (not "int") to list
  
  Can someone help me with this error ?
  </code></pre>