title: how to check if a change is not present in both "invalid_change" and "changes_not_in_manifest" lists
body: <p>I am having the following python block where i want to check if a change doesnt exist in invalid_change and changes_not_in_manifest lists,the problem I am facing is as soon as the try loop is entered and checked for 
  invalid_change.index(change) it goes to except,how do I check if a change is not present in both "invalid_change" and "changes_not_in_manifest" lists?</p>
  
  <pre><code>try: # check if invalid change is present
    invalid_change.index(change)
    changes_not_in_manifest.index(change)
    print "invalid list"
    ifvalid = False
    break
  except:
    print "except"
    pass
  </code></pre>