randomize_module: pep8 cleanup

common/lib/xmodule/xmodule/randomize_module.py

@@ -14,12 +14,14 @@ log = logging.getLogger('edx.' + __name__)
 
 
 class RandomizeFields(object):
-    choice = Integer(help="Which random child was chosen", scope=Scope.user_state)
+    choice = Integer(help="Which random child was chosen",
+                     scope=Scope.user_state)
 
 
 class RandomizeModule(RandomizeFields, XModule):
     """
-    Chooses a random child module.  Chooses the same one every time for each student.
+    Chooses a random child module. Chooses the same one every time for each
+    student.
 
      Example:
      <randomize>
@@ -29,34 +31,41 @@ class RandomizeModule(RandomizeFields, XModule):
      </randomize>
 
     User notes:
-
-      - If you're randomizing amongst graded modules, each of them MUST be worth the same
-        number of points.  Otherwise, the earth will be overrun by monsters from the
-        deeps.  You have been warned.
+      - If you're randomizing amongst graded modules, each of them MUST be
+        worth the same number of points. Otherwise, the earth will be overrun
+        by monsters from the deeps. You have been warned.
 
     Technical notes:
-      - There is more dark magic in this code than I'd like.  The whole varying-children +
-        grading interaction is a tangle between super and subclasses of descriptors and
-        modules.
-"""
+      - There is more dark magic in this code than I'd like. The whole
+        varying-children + grading interaction is a tangle between super and
+        subclasses of descriptors and modules.
+    """
     def __init__(self, *args, **kwargs):
         super(RandomizeModule, self).__init__(*args, **kwargs)
-
-        # NOTE: calling self.get_children() creates a circular reference--
-        # it calls get_child_descriptors() internally, but that doesn't work until
-        # we've picked a choice
-        num_choices = len(self.descriptor.get_children())
+        # NOTE: calling self.get_children() creates a circular reference --
+        # it calls get_child_descriptors() internally, but that doesn't work
+        # until we've picked a choice
+        # import pudb; pudb.set_trace()
+        children = self.descriptor.get_children()
+        xml_attrs = self.descriptor.xml_attributes or []
+        use_randrange = 'use_randrange' in xml_attrs
+        # TODO: use this attr to toggle storing history and never showing the
+        # same problem twice
+        # no_repeats = xml_attrs.has_key('no_repeats')
+        num_choices = len(children)
 
         if self.choice > num_choices:
             # Oops.  Children changed. Reset.
             self.choice = None
 
         if self.choice is None:
-            # choose one based on the system seed, or randomly if that's not available
+            # choose one based on the system seed, or randomly if that's not
+            # available
             if num_choices > 0:
-                if self.system.seed is not None and 'use_randrange' not in (self.descriptor.xml_attributes or []):
+                if self.system.seed is not None and not use_randrange:
                     self.choice = self.system.seed % num_choices
-                    log.debug('using seed for %s choice=%s' % (str(self.location), self.choice))
+                    log.debug('using seed for %s choice=%s' %
+                              (str(self.location), self.choice))
                 else:
                     self.choice = random.randrange(0, num_choices)
                     log.debug('using randrange for %s' % str(self.location))
@@ -66,8 +75,9 @@ class RandomizeModule(RandomizeFields, XModule):
         if self.choice is not None:
             self.child_descriptor = self.descriptor.get_children()[self.choice]
             # Now get_children() should return a list with one element
-            log.debug("choice=%s in %s, children of randomize module (should be only 1): %s",
-                      self.choice, str(self.location), self.get_children())
+            log.debug("choice=%s in %s, children of randomize module "
+                      "(should be only 1): %s", self.choice,
+                      str(self.location), self.get_children())
             self.child = self.get_children()[0]
         else:
             self.child_descriptor = None
@@ -79,32 +89,32 @@ class RandomizeModule(RandomizeFields, XModule):
         """
         if self.child_descriptor is None:
             return []
-
         return [self.child_descriptor]
 
-
     def student_view(self, context):
         if self.child is None:
-            # raise error instead?  In fact, could complain on descriptor load...
+            # raise error instead?  In fact, could complain on descriptor load
             return Fragment(content=u"<div>Nothing to randomize between</div>")
-
+        child_html = self.child.render('student_view', context)
         if self.system.user_is_staff:
             dishtml = self.system.render_template('randomize_control.html', {
-                    'element_id': self.location.html_id(),
-                    'is_staff': self.system.user_is_staff,
-                    'ajax_url': self.system.ajax_url,
-                    'choice': self.choice,
-                    'num_choices': len(self.descriptor.get_children()),
-                    })
-            # html = '<html><p>Welcome, staff.  Randomize loc=%s ; Choice=%s</p><br/><hr/></br/>' % (str(self.location), self.choice)
-            child_html = self.child.render('student_view', context)
-            return Fragment(u"<html>" + dishtml + child_html.content + u"</html>")
-        return self.child.render('student_view', context)
+                'element_id': self.location.html_id(),
+                'is_staff': self.system.user_is_staff,
+                'ajax_url': self.system.ajax_url,
+                'choice': self.choice,
+                'num_choices': len(self.descriptor.get_children()),
+            })
+            # html = '<html><p>Welcome, staff.  Randomize loc=%s ;
+            # Choice=%s</p><br/><hr/></br/>' % (str(self.location),
+            # self.choice)
+            return Fragment(u"<html>" + dishtml + child_html.content +
+                            u"</html>")
+        return child_html
 
     def handle_ajax(self, dispatch, data):
-        if dispatch=='next':
+        if dispatch == 'next':
             self.choice = self.choice + 1
-        elif dispatch=='jump':
+        elif dispatch == 'jump':
             log.debug('jump, data=%s' % data)
             self.choice = int(data['choice'])
         num_choices = len(self.descriptor.get_children())
@@ -119,14 +129,12 @@ class RandomizeModule(RandomizeFields, XModule):
 
 
 class RandomizeDescriptor(RandomizeFields, SequenceDescriptor):
-    # the editing interface can be the same as for sequences -- just a container
+    # the editing interface can be the same as for sequences -- just a
+    # container
     module_class = RandomizeModule
-
     filename_extension = "xml"
 
-
     def definition_to_xml(self, resource_fs):
-
         xml_object = etree.Element('randomize')
         for child in self.get_children():
             self.runtime.add_block_as_child_node(child, xml_object)
@@ -134,7 +142,7 @@ class RandomizeDescriptor(RandomizeFields, SequenceDescriptor):
 
     def has_dynamic_children(self):
         """
-        Grading needs to know that only one of the children is actually "real".  This
-        makes it use module.get_child_descriptors().
+        Grading needs to know that only one of the children is actually "real".
+        This makes it use module.get_child_descriptors().
         """
         return True