title: Passing a variable to a command - not enough arguments for format string
body: <p>hi I have the following block of test code (test lab).</p>
  
  <pre><code>#&lt;snip&gt;
  client_mac = 'f8:cf:c5:a4:a2:84'
  #&lt;snip&gt;
  # issue a command1
  my_command_output1 = my_wlc_session.sendcommand("grep include f8:cf:c5:a4:a2:84 \"show client summary\" \n")
  # print the output
  print(my_command_output1)
  #
  # issue a command2
  my_command_output2 = my_wlc_session.sendcommand("grep include %s \"show client summary\" \n") % client_mac
  # print the output
  print(my_command_output2)
  #&lt;snip&gt;
  </code></pre>
  
  <p>Command1 works as expected.</p>
  
  <p>But command2 is the issue. I want some way of passing the client_mac to the command, but the code I am using results in this;</p>
  
  <pre><code>TypeError: not enough arguments for format string
  </code></pre>
  
  <p>I think this is something to do with the /n , but I need a 2nd new-line after the command for it to be executed.</p>
  
  <p>Is there a better way of passing the client_mac? Or am I doing something else wrong.</p>