title: argument 2 to map() must support iteration while using celery
body: <p>I am calling the task as a group like this:</p>
  
  <pre><code>celery.group(getting_a_page.s(user, i,post) for i in range(no_of_pages))().get()
  </code></pre>
  
  <p>This is my task:</p>
  
  <pre><code>@task(ignore_result=True)
      def getting_a_page(user,page_no,post):
  
          print "getting a posterous page"
  
          return True
  </code></pre>
  
  <p>Where am I going wrong? What does this error mean?</p>
  
  <p>Edit:</p>
  
  <p>Error message:</p>
  
  <pre><code>/home/migrate/migrate/../migrate/apps/migrateuser/views.py" in start_migration
    72.   getting_a_page(user)
  File "/home/migrate/migrate/apps/posting_app/posting.py" in posterours_get_pages_task
    21.   celery.group(getting_a_page.s(user, i,post) for i in range(no_of_pages))().get()
  File "/usr/local/lib/python2.7/dist-packages/celery/canvas.py" in __call__
    316.                     map(Signature.clone, self.tasks), partial_args)
  </code></pre>