title: sending a complex shell command to python subprocess
body: <p>I'm writing a script that uses a series of complex Imagemagick commands in python. 
  I'm wondering how to call something like this...</p>
  
  <p><code>convert 1.png \( +clone -background black -shadow 110x1+9+9 \) +swap -background none -layers merge +repage 2.png</code> </p>
  
  <p>I am perfectly comfortable calling simple commands with subprocess, but I do not yet know how to specify the order of execution (the escaped parentheses). </p>
  
  <p>Surely I could use os.system or the commands module, but since these are leaving the language, I would definitely prefer to use subprocess. </p>