title: python subprocess.call arguments issue
body: <p>I am writing a simple python script under Linux to do a batch of concurrent single pings to hosts on my subnet using <code>subprocess</code>.</p>
  
  <p>Manually the command works:
  <code>ping -c 1 192.168.68.1</code></p>
  
  <p>The script::</p>
  
  <pre><code>#!/usr/bin/python
  from subprocess import call
  
  path = "ping"
  flags = "-c 1 "
  
  for i in range(1,3):
      ip_addr = "192.168.68." + str(i)
      args = flags + ip_addr
  
      print "doing: {} {}".format(path, args)        
      call([path, args])
  </code></pre>
  
  <p>Commenting out call outputs the expected:</p>
  
  <pre><code>doing: ping -c 1 192.168.68.1
  doing: ping -c 1 192.168.68.2
  </code></pre>
  
  <p>With <code>call()</code>, the script seems to call ping but with unknown arguments. Output as follows:</p>
  
  <pre><code>doing: ping -c 1 192.168.68.1
  Usage: ping [-aAbBdDfhLnOqrRUvV64] [-c count] [-i interval] [-I interface]
          [-m mark] [-M pmtudisc_option] [-l preload] [-p pattern] [-Q tos]
          [-s packetsize] [-S sndbuf] [-t ttl] [-T timestamp_option]
          [-w deadline] [-W timeout] [hop1 ...] destination
  Usage: ping -6 [-aAbBdDfhLnOqrRUvV] [-c count] [-i interval] [-I interface]
           [-l preload] [-m mark] [-M pmtudisc_option]
           [-N nodeinfo_option] [-p pattern] [-Q tclass] [-s packetsize]
           [-S sndbuf] [-t ttl] [-T timestamp_option] [-w deadline]
           [-W timeout] destination
  doing: ping -c 1 192.168.68.2
  Usage: ping [-aAbBdDfhLnOqrRUvV64] [-c count] [-i interval] [-I interface]
          [-m mark] [-M pmtudisc_option] [-l preload] [-p pattern] [-Q tos]
          [-s packetsize] [-S sndbuf] [-t ttl] [-T timestamp_option]
          [-w deadline] [-W timeout] [hop1 ...] destination
  Usage: ping -6 [-aAbBdDfhLnOqrRUvV] [-c count] [-i interval] [-I interface]
           [-l preload] [-m mark] [-M pmtudisc_option]
           [-N nodeinfo_option] [-p pattern] [-Q tclass] [-s packetsize]
           [-S sndbuf] [-t ttl] [-T timestamp_option] [-w deadline]
           [-W timeout] destination
  </code></pre>
  
  <p>It seems <code>ping</code> is being called twice for each iteration with different <code>args</code> to what I expect. I note the <code>-6</code> argument ping complains about.<br>I would appreciate any help, particularly with regard to using <code>call()</code> properly.</p>
  
  <p><strong>Update:</strong><br>
  Added bash script I'm attempting to emulate:</p>
  
  <pre><code>#!/bin/bash
  for ip in $(seq 1 2); do
      ping -c 1 192.168.68.$ip &amp;
  done
  </code></pre>