Line length and doc string cleanups

* no functionality changed in this commit.

common/lib/xmodule/xmodule/backcompat_module.py

@@ -12,8 +12,8 @@ log = logging.getLogger(__name__)
 def process_includes(fn):
     """
     Wraps a XModuleDescriptor.from_xml method, and modifies xml_data to replace
-    any immediate child <include> items with the contents of the file that they are
-    supposed to include
+    any immediate child <include> items with the contents of the file that they
+    are supposed to include
     """
     @wraps(fn)
     def from_xml(cls, xml_data, system, org=None, course=None):
@@ -25,15 +25,19 @@ def process_includes(fn):
                 try:
                     ifp = system.resources_fs.open(file)
                 except Exception:
-                    log.exception('Error in problem xml include: %s' % (etree.tostring(next_include, pretty_print=True)))
-                    log.exception('Cannot find file %s in %s' % (file, dir))
+                    msg = 'Error in problem xml include: %s\n' % (
+                        etree.tostring(next_include, pretty_print=True))
+                    msg += 'Cannot find file %s in %s' % (file, dir)
+                    log.exception(msg)
                     raise
                 try:
                     # read in and convert to XML
                     incxml = etree.XML(ifp.read())
                 except Exception:
-                    log.exception('Error in problem xml include: %s' % (etree.tostring(next_include, pretty_print=True)))
-                    log.exception('Cannot parse XML in %s' % (file))
+                    msg = 'Error in problem xml include: %s\n' % (
+                        etree.tostring(next_include, pretty_print=True))
+                    msg += 'Cannot parse XML in %s' % (file)
+                    log.exception(msg)
                     raise
                 # insert  new XML into tree in place of inlcude
                 parent = next_include.getparent()
@@ -50,8 +54,8 @@ class SemanticSectionDescriptor(XModuleDescriptor):
     @process_includes
     def from_xml(cls, xml_data, system, org=None, course=None):
         """
-        Removes sections single child elements in favor of just embedding the child element
-
+        Removes sections with single child elements in favor of just embedding
+        the child element
         """
         xml_object = etree.fromstring(xml_data)
 

common/lib/xmodule/xmodule/capa_module.py

@@ -67,7 +67,8 @@ class ComplexEncoder(json.JSONEncoder):
 
 class CapaModule(XModule):
     '''
-    An XModule implementing LonCapa format problems, implemented by way of capa.capa_problem.LoncapaProblem
+    An XModule implementing LonCapa format problems, implemented by way of
+    capa.capa_problem.LoncapaProblem
     '''
     icon_class = 'problem'
 
@@ -77,8 +78,10 @@ class CapaModule(XModule):
     js_module_name = "Problem"
     css = {'scss': [resource_string(__name__, 'css/capa/display.scss')]}
 
-    def __init__(self, system, location, definition, instance_state=None, shared_state=None, **kwargs):
-        XModule.__init__(self, system, location, definition, instance_state, shared_state, **kwargs)
+    def __init__(self, system, location, definition, instance_state=None,
+                 shared_state=None, **kwargs):
+        XModule.__init__(self, system, location, definition, instance_state,
+                         shared_state, **kwargs)
 
         self.attempts = 0
         self.max_attempts = None
@@ -133,7 +136,8 @@ class CapaModule(XModule):
             seed = None
 
         try:
-            self.lcp = LoncapaProblem(self.definition['data'], self.location.html_id(), instance_state, seed=seed, system=self.system)
+            self.lcp = LoncapaProblem(self.definition['data'], self.location.html_id(),
+                                      instance_state, seed=seed, system=self.system)
         except Exception:
             msg = 'cannot create LoncapaProblem %s' % self.location.url()
             log.exception(msg)
@@ -141,15 +145,20 @@ class CapaModule(XModule):
                 msg = '<p>%s</p>' % msg.replace('<', '&lt;')
                 msg += '<p><pre>%s</pre></p>' % traceback.format_exc().replace('<', '&lt;')
                 # create a dummy problem with error message instead of failing
-                problem_text = '<problem><text><font color="red" size="+2">Problem %s has an error:</font>%s</text></problem>' % (self.location.url(), msg)
-                self.lcp = LoncapaProblem(problem_text, self.location.html_id(), instance_state, seed=seed, system=self.system)
+                problem_text = ('<problem><text><font color="red" size="+2">'
+                                'Problem %s has an error:</font>%s</text></problem>' %
+                                (self.location.url(), msg))
+                self.lcp = LoncapaProblem(
+                    problem_text, self.location.html_id(),
+                    instance_state, seed=seed, system=self.system)
             else:
                 raise
 
     @property
     def rerandomize(self):
         """
-        Property accessor that returns self.metadata['rerandomize'] in a canonical form
+        Property accessor that returns self.metadata['rerandomize'] in a
+        canonical form
         """
         rerandomize = self.metadata.get('rerandomize', 'always')
         if rerandomize in ("", "always", "true"):
@@ -203,7 +212,10 @@ class CapaModule(XModule):
         except Exception, err:
             if self.system.DEBUG:
                 log.exception(err)
-                msg = '[courseware.capa.capa_module] <font size="+1" color="red">Failed to generate HTML for problem %s</font>' % (self.location.url())
+                msg = (
+                    '[courseware.capa.capa_module] <font size="+1" color="red">'
+                    'Failed to generate HTML for problem %s</font>' %
+                    (self.location.url()))
                 msg += '<p>Error:</p><p><pre>%s</pre></p>' % str(err).replace('<', '&lt;')
                 msg += '<p><pre>%s</pre></p>' % traceback.format_exc().replace('<', '&lt;')
                 html = msg
@@ -215,8 +227,8 @@ class CapaModule(XModule):
                    'weight': self.weight,
                   }
 
-        # We using strings as truthy values, because the terminology of the check button
-        # is context-specific.
+        # We using strings as truthy values, because the terminology of the
+        # check button is context-specific.
         check_button = "Grade" if self.max_attempts else "Check"
         reset_button = True
         save_button = True
@@ -242,7 +254,8 @@ class CapaModule(XModule):
         if not self.lcp.done:
             reset_button = False
 
-        # We don't need a "save" button if infinite number of attempts and non-randomized
+        # We don't need a "save" button if infinite number of attempts and
+        # non-randomized
         if self.max_attempts is None and self.rerandomize != "always":
             save_button = False
 

common/lib/xmodule/xmodule/course_module.py

@@ -17,11 +17,12 @@ class CourseDescriptor(SequenceDescriptor):
         try:
             self.start = time.strptime(self.metadata["start"], "%Y-%m-%dT%H:%M")
         except KeyError:
-            self.start = time.gmtime(0)  # The epoch
-            log.critical("Course loaded without a start date. " + str(self.id))
-        except ValueError, e:
-            self.start = time.gmtime(0)  # The epoch
-            log.critical("Course loaded with a bad start date. " + str(self.id) + " '" + str(e) + "'")
+            self.start = time.gmtime(0) #The epoch
+            log.critical("Course loaded without a start date. %s", self.id)
+        except ValueError as e:
+            self.start = time.gmtime(0) #The epoch
+            log.critical("Course loaded with a bad start date. %s '%s'",
+                         self.id, e)
 
     def has_started(self):
         return time.gmtime() > self.start

common/lib/xmodule/xmodule/mako_module.py

@@ -19,7 +19,9 @@ class MakoModuleDescriptor(XModuleDescriptor):
 
     def __init__(self, system, definition=None, **kwargs):
         if getattr(system, 'render_template', None) is None:
-            raise TypeError('{system} must have a render_template function in order to use a MakoDescriptor'.format(system=system))
+            raise TypeError('{system} must have a render_template function'
+                            ' in order to use a MakoDescriptor'.format(
+                    system=system))
         super(MakoModuleDescriptor, self).__init__(system, definition, **kwargs)
 
     def get_context(self):
@@ -29,4 +31,5 @@ class MakoModuleDescriptor(XModuleDescriptor):
         return {'module': self}
 
     def get_html(self):
-        return self.system.render_template(self.mako_template, self.get_context())
+        return self.system.render_template(
+            self.mako_template, self.get_context())

common/lib/xmodule/xmodule/modulestore/__init__.py

@@ -45,13 +45,17 @@ class Location(_LocationBase):
         """
         return re.sub('_+', '_', INVALID_CHARS.sub('_', value))
 
-    def __new__(_cls, loc_or_tag=None, org=None, course=None, category=None, name=None, revision=None):
+    def __new__(_cls, loc_or_tag=None, org=None, course=None, category=None,
+                name=None, revision=None):
         """
         Create a new location that is a clone of the specifed one.
 
         location - Can be any of the following types:
-            string: should be of the form {tag}://{org}/{course}/{category}/{name}[/{revision}]
+            string: should be of the form
+                    {tag}://{org}/{course}/{category}/{name}[/{revision}]
+
             list: should be of the form [tag, org, course, category, name, revision]
+
             dict: should be of the form {
                 'tag': tag,
                 'org': org,
@@ -62,16 +66,19 @@ class Location(_LocationBase):
             }
             Location: another Location object
 
-        In both the dict and list forms, the revision is optional, and can be ommitted.
+        In both the dict and list forms, the revision is optional, and can be
+        ommitted.
 
-        Components must be composed of alphanumeric characters, or the characters '_', '-', and '.'
+        Components must be composed of alphanumeric characters, or the
+        characters '_', '-', and '.'
 
-        Components may be set to None, which may be interpreted by some contexts to mean
-        wildcard selection
+        Components may be set to None, which may be interpreted by some contexts
+        to mean wildcard selection
         """
 
 
-        if org is None and course is None and category is None and name is None and revision is None:
+        if (org is None and course is None and category is None and
+            name is None and revision is None):
             location = loc_or_tag
         else:
             location = (loc_or_tag, org, course, category, name, revision)
@@ -131,9 +138,11 @@ class Location(_LocationBase):
 
     def html_id(self):
         """
-        Return a string with a version of the location that is safe for use in html id attributes
+        Return a string with a version of the location that is safe for use in
+        html id attributes
         """
-        return "-".join(str(v) for v in self.list() if v is not None).replace('.', '_')
+        return "-".join(str(v) for v in self.list()
+                        if v is not None).replace('.', '_')
 
     def dict(self):
         """
@@ -154,7 +163,8 @@ class Location(_LocationBase):
 
 class ModuleStore(object):
     """
-    An abstract interface for a database backend that stores XModuleDescriptor instances
+    An abstract interface for a database backend that stores XModuleDescriptor
+    instances
     """
     def get_item(self, location, depth=0):
         """
@@ -164,13 +174,16 @@ class ModuleStore(object):
 
         If any segment of the location is None except revision, raises
             xmodule.modulestore.exceptions.InsufficientSpecificationError
-        If no object is found at that location, raises xmodule.modulestore.exceptions.ItemNotFoundError
+
+        If no object is found at that location, raises
+            xmodule.modulestore.exceptions.ItemNotFoundError
 
         location: Something that can be passed to Location
 
-        depth (int): An argument that some module stores may use to prefetch descendents of the queried modules
-            for more efficient results later in the request. The depth is counted in the number of
-            calls to get_children() to cache. None indicates to cache all descendents
+        depth (int): An argument that some module stores may use to prefetch
+            descendents of the queried modules for more efficient results later
+            in the request. The depth is counted in the number of calls to
+            get_children() to cache. None indicates to cache all descendents
         """
         raise NotImplementedError
 
@@ -182,9 +195,10 @@ class ModuleStore(object):
 
         location: Something that can be passed to Location
 
-        depth: An argument that some module stores may use to prefetch descendents of the queried modules
-            for more efficient results later in the request. The depth is counted in the number of calls
-            to get_children() to cache. None indicates to cache all descendents
+        depth: An argument that some module stores may use to prefetch
+            descendents of the queried modules for more efficient results later
+            in the request. The depth is counted in the number of calls to
+            get_children() to cache. None indicates to cache all descendents
         """
         raise NotImplementedError
 
@@ -228,4 +242,3 @@ class ModuleStore(object):
         in this modulestore.
         '''
         raise NotImplementedError
-

common/lib/xmodule/xmodule/raw_module.py

@@ -8,7 +8,7 @@ log = logging.getLogger(__name__)
 
 class RawDescriptor(MakoModuleDescriptor, XmlDescriptor):
     """
-    Module that provides a raw editing view of it's data and children
+    Module that provides a raw editing view of its data and children
     """
     mako_template = "widgets/raw-edit.html"
 

common/lib/xmodule/xmodule/seq_module.py

@@ -20,12 +20,15 @@ class_priority = ['video', 'problem']
 class SequenceModule(XModule):
     ''' Layout module which lays out content in a temporal sequence
     '''
-    js = {'coffee': [resource_string(__name__, 'js/src/sequence/display.coffee')]}
+    js = {'coffee': [resource_string(__name__,
+                                     'js/src/sequence/display.coffee')]}
     css = {'scss': [resource_string(__name__, 'css/sequence/display.scss')]}
     js_module_name = "Sequence"
 
-    def __init__(self, system, location, definition, instance_state=None, shared_state=None, **kwargs):
-        XModule.__init__(self, system, location, definition, instance_state, shared_state, **kwargs)
+    def __init__(self, system, location, definition, instance_state=None,
+                 shared_state=None, **kwargs):
+        XModule.__init__(self, system, location, definition,
+                         instance_state, shared_state, **kwargs)
         self.position = 1
 
         if instance_state is not None:
@@ -92,7 +95,8 @@ class SequenceModule(XModule):
         self.rendered = True
 
     def get_icon_class(self):
-        child_classes = set(child.get_icon_class() for child in self.get_children())
+        child_classes = set(child.get_icon_class()
+                            for child in self.get_children())
         new_class = 'other'
         for c in class_priority:
             if c in child_classes:
@@ -114,5 +118,6 @@ class SequenceDescriptor(MakoModuleDescriptor, XmlDescriptor):
     def definition_to_xml(self, resource_fs):
         xml_object = etree.Element('sequential')
         for child in self.get_children():
-            xml_object.append(etree.fromstring(child.export_to_xml(resource_fs)))
+            xml_object.append(
+                etree.fromstring(child.export_to_xml(resource_fs)))
         return xml_object

common/lib/xmodule/xmodule/x_module.py

@@ -31,23 +31,28 @@ class Plugin(object):
     def load_class(cls, identifier, default=None):
         """
         Loads a single class instance specified by identifier. If identifier
-        specifies more than a single class, then logs a warning and returns the first
-        class identified.
+        specifies more than a single class, then logs a warning and returns the
+        first class identified.
 
-        If default is not None, will return default if no entry_point matching identifier
-        is found. Otherwise, will raise a ModuleMissingError
+        If default is not None, will return default if no entry_point matching
+        identifier is found. Otherwise, will raise a ModuleMissingError
         """
         if cls._plugin_cache is None:
             cls._plugin_cache = {}
 
         if identifier not in cls._plugin_cache:
             identifier = identifier.lower()
-            classes = list(pkg_resources.iter_entry_points(cls.entry_point, name=identifier))
+            classes = list(pkg_resources.iter_entry_points(
+                    cls.entry_point, name=identifier))
+
             if len(classes) > 1:
-                log.warning("Found multiple classes for {entry_point} with identifier {id}: {classes}. Returning the first one.".format(
+                log.warning("Found multiple classes for {entry_point} with "
+                            "identifier {id}: {classes}. "
+                            "Returning the first one.".format(
                     entry_point=cls.entry_point,
                     id=identifier,
-                    classes=", ".join(class_.module_name for class_ in classes)))
+                    classes=", ".join(
+                            class_.module_name for class_ in classes)))
 
             if len(classes) == 0:
                 if default is not None:
@@ -79,9 +84,12 @@ class HTMLSnippet(object):
     def get_javascript(cls):
         """
         Return a dictionary containing some of the following keys:
+
             coffee: A list of coffeescript fragments that should be compiled and
                     placed on the page
-            js: A list of javascript fragments that should be included on the page
+
+            js: A list of javascript fragments that should be included on the
+            page
 
         All of these will be loaded onto the page in the CMS
         """
@@ -91,12 +99,15 @@ class HTMLSnippet(object):
     def get_css(cls):
         """
         Return a dictionary containing some of the following keys:
-            css: A list of css fragments that should be applied to the html contents
-                 of the snippet
-            sass: A list of sass fragments that should be applied to the html contents
-                  of the snippet
-            scss: A list of scss fragments that should be applied to the html contents
-                  of the snippet
+
+            css: A list of css fragments that should be applied to the html
+                 contents of the snippet
+
+            sass: A list of sass fragments that should be applied to the html
+                  contents of the snippet
+
+            scss: A list of scss fragments that should be applied to the html
+                  contents of the snippet
         """
         return cls.css
 
@@ -104,47 +115,70 @@ class HTMLSnippet(object):
         """
         Return the html used to display this snippet
         """
-        raise NotImplementedError("get_html() must be provided by specific modules - not present in {0}"
+        raise NotImplementedError(
+            "get_html() must be provided by specific modules - not present in {0}"
                                   .format(self.__class__))
 
 
 class XModule(HTMLSnippet):
     ''' Implements a generic learning module.
 
-        Subclasses must at a minimum provide a definition for get_html in order to be displayed to users.
+        Subclasses must at a minimum provide a definition for get_html in order
+        to be displayed to users.
 
         See the HTML module for a simple example.
     '''
 
-    # The default implementation of get_icon_class returns the icon_class attribute of the class
-    # This attribute can be overridden by subclasses, and the function can also be overridden
-    # if the icon class depends on the data in the module
+    # The default implementation of get_icon_class returns the icon_class
+    # attribute of the class
+    #
+    # This attribute can be overridden by subclasses, and
+    # the function can also be overridden if the icon class depends on the data
+    # in the module
     icon_class = 'other'
 
-    def __init__(self, system, location, definition, instance_state=None, shared_state=None, **kwargs):
+    def __init__(self, system, location, definition,
+                 instance_state=None, shared_state=None, **kwargs):
         '''
         Construct a new xmodule
 
         system: A ModuleSystem allowing access to external resources
+
         location: Something Location-like that identifies this xmodule
-        definition: A dictionary containing 'data' and 'children'. Both are optional
-            'data': is JSON-like (string, dictionary, list, bool, or None, optionally nested).
-                This defines all of the data necessary for a problem to display that is intrinsic to the problem.
-                It should not include any data that would vary between two courses using the same problem
+
+        definition: A dictionary containing 'data' and 'children'. Both are
+        optional
+
+            'data': is JSON-like (string, dictionary, list, bool, or None,
+                optionally nested).
+
+                This defines all of the data necessary for a problem to display
+                that is intrinsic to the problem.  It should not include any
+                data that would vary between two courses using the same problem
                 (due dates, grading policy, randomization, etc.)
-            'children': is a list of Location-like values for child modules that this module depends on
-        instance_state: A string of serialized json that contains the state of this module for
-            current student accessing the system, or None if no state has been saved
-        shared_state: A string of serialized json that contains the state that is shared between
-            this module and any modules of the same type with the same shared_state_key. This
-            state is only shared per-student, not across different students
-        kwargs: Optional arguments. Subclasses should always accept kwargs and pass them
-            to the parent class constructor.
+
+            'children': is a list of Location-like values for child modules that
+                this module depends on
+
+        instance_state: A string of serialized json that contains the state of
+                this module for current student accessing the system, or None if
+                no state has been saved
+
+        shared_state: A string of serialized json that contains the state that
+            is shared between this module and any modules of the same type with
+            the same shared_state_key. This state is only shared per-student,
+            not across different students
+
+        kwargs: Optional arguments. Subclasses should always accept kwargs and
+            pass them to the parent class constructor.
+
             Current known uses of kwargs:
-                metadata: SCAFFOLDING - This dictionary will be split into several different types of metadata
-                    in the future (course policy, modification history, etc).
-                    A dictionary containing data that specifies information that is particular
-                    to a problem in the context of a course
+
+                metadata: SCAFFOLDING - This dictionary will be split into
+                    several different types of metadata in the future (course
+                    policy, modification history, etc).  A dictionary containing
+                    data that specifies information that is particular to a
+                    problem in the context of a course
         '''
         self.system = system
         self.location = Location(location)
@@ -217,16 +251,21 @@ class XModule(HTMLSnippet):
 
     def max_score(self):
         ''' Maximum score. Two notes:
-            * This is generic; in abstract, a problem could be 3/5 points on one randomization, and 5/7 on another
-            * In practice, this is a Very Bad Idea, and (a) will break some code in place (although that code
-              should get fixed), and (b) break some analytics we plan to put in place.
+
+            * This is generic; in abstract, a problem could be 3/5 points on one
+              randomization, and 5/7 on another
+
+            * In practice, this is a Very Bad Idea, and (a) will break some code
+              in place (although that code should get fixed), and (b) break some
+              analytics we plan to put in place.
         '''
         return None
 
     def get_progress(self):
-        ''' Return a progress.Progress object that represents how far the student has gone
-        in this module.  Must be implemented to get correct progress tracking behavior in
-        nesting modules like sequence and vertical.
+        ''' Return a progress.Progress object that represents how far the
+        student has gone in this module.  Must be implemented to get correct
+        progress tracking behavior in nesting modules like sequence and
+        vertical.
 
         If this module has no notion of progress, return None.
         '''
@@ -240,13 +279,14 @@ class XModule(HTMLSnippet):
 
 class XModuleDescriptor(Plugin, HTMLSnippet):
     """
-    An XModuleDescriptor is a specification for an element of a course. This could
-    be a problem, an organizational element (a group of content), or a segment of video,
-    for example.
-
-    XModuleDescriptors are independent and agnostic to the current student state on a
-    problem. They handle the editing interface used by instructors to create a problem,
-    and can generate XModules (which do know about student state).
+    An XModuleDescriptor is a specification for an element of a course. This
+    could be a problem, an organizational element (a group of content), or a
+    segment of video, for example.
+
+    XModuleDescriptors are independent and agnostic to the current student state
+    on a problem. They handle the editing interface used by instructors to
+    create a problem, and can generate XModules (which do know about student
+    state).
     """
     entry_point = "xmodule.v1"
     module_class = XModule
@@ -255,46 +295,58 @@ class XModuleDescriptor(Plugin, HTMLSnippet):
     inheritable_metadata = (
         'graded', 'start', 'due', 'graceperiod', 'showanswer', 'rerandomize',
 
-        # This is used by the XMLModuleStore to provide for locations for static files,
-        # and will need to be removed when that code is removed
+        # TODO: This is used by the XMLModuleStore to provide for locations for
+        # static files, and will need to be removed when that code is removed
         'data_dir'
     )
 
-    # A list of descriptor attributes that must be equal for the descriptors to be
-    # equal
-    equality_attributes = ('definition', 'metadata', 'location', 'shared_state_key', '_inherited_metadata')
+    # A list of descriptor attributes that must be equal for the descriptors to
+    # be equal
+    equality_attributes = ('definition', 'metadata', 'location',
+                           'shared_state_key', '_inherited_metadata')
 
-    # ============================= STRUCTURAL MANIPULATION ===========================
+    # ============================= STRUCTURAL MANIPULATION ===================
     def __init__(self,
                  system,
                  definition=None,
                  **kwargs):
         """
         Construct a new XModuleDescriptor. The only required arguments are the
-        system, used for interaction with external resources, and the definition,
-        which specifies all the data needed to edit and display the problem (but none
-        of the associated metadata that handles recordkeeping around the problem).
+        system, used for interaction with external resources, and the
+        definition, which specifies all the data needed to edit and display the
+        problem (but none of the associated metadata that handles recordkeeping
+        around the problem).
+
+        This allows for maximal flexibility to add to the interface while
+        preserving backwards compatibility.
 
-        This allows for maximal flexibility to add to the interface while preserving
-        backwards compatibility.
+        system: A DescriptorSystem for interacting with external resources
 
-        system: An XModuleSystem for interacting with external resources
-        definition: A dict containing `data` and `children` representing the problem definition
+        definition: A dict containing `data` and `children` representing the
+        problem definition
 
         Current arguments passed in kwargs:
-            location: A xmodule.modulestore.Location object indicating the name and ownership of this problem
-            shared_state_key: The key to use for sharing StudentModules with other
-                modules of this type
+
+            location: A xmodule.modulestore.Location object indicating the name
+                and ownership of this problem
+
+            shared_state_key: The key to use for sharing StudentModules with
+                other modules of this type
+
             metadata: A dictionary containing the following optional keys:
-                goals: A list of strings of learning goals associated with this module
-                display_name: The name to use for displaying this module to the user
+                goals: A list of strings of learning goals associated with this
+                    module
+                display_name: The name to use for displaying this module to the
+                    user
                 format: The format of this module ('Homework', 'Lab', etc)
                 graded (bool): Whether this module is should be graded or not
                 start (string): The date for which this module will be available
                 due (string): The due date for this module
-                graceperiod (string): The amount of grace period to allow when enforcing the due date
+                graceperiod (string): The amount of grace period to allow when
+                    enforcing the due date
                 showanswer (string): When to show answers for this module
-                rerandomize (string): When to generate a newly randomized instance of the module data
+                rerandomize (string): When to generate a newly randomized
+                    instance of the module data
         """
         self.system = system
         self.metadata = kwargs.get('metadata', {})
@@ -321,7 +373,8 @@ class XModuleDescriptor(Plugin, HTMLSnippet):
                 self.metadata[attr] = metadata[attr]
 
     def get_children(self):
-        """Returns a list of XModuleDescriptor instances for the children of this module"""
+        """Returns a list of XModuleDescriptor instances for the children of
+        this module"""
         if self._child_instances is None:
             self._child_instances = []
             for child_loc in self.definition.get('children', []):
@@ -333,8 +386,9 @@ class XModuleDescriptor(Plugin, HTMLSnippet):
 
     def xmodule_constructor(self, system):
         """
-        Returns a constructor for an XModule. This constructor takes two arguments:
-        instance_state and shared_state, and returns a fully nstantiated XModule
+        Returns a constructor for an XModule. This constructor takes two
+        arguments: instance_state and shared_state, and returns a fully
+        instantiated XModule
         """
         return partial(
             self.module_class,
@@ -344,7 +398,7 @@ class XModuleDescriptor(Plugin, HTMLSnippet):
             metadata=self.metadata
         )
 
-    # ================================= JSON PARSING ===================================
+    # ================================= JSON PARSING ===========================
     @staticmethod
     def load_from_json(json_data, system, default_class=None):
         """
@@ -366,13 +420,14 @@ class XModuleDescriptor(Plugin, HTMLSnippet):
         Creates an instance of this descriptor from the supplied json_data.
         This may be overridden by subclasses
 
-        json_data: A json object specifying the definition and any optional keyword arguments for
-            the XModuleDescriptor
-        system: An XModuleSystem for interacting with external resources
+        json_data: A json object specifying the definition and any optional
+            keyword arguments for the XModuleDescriptor
+
+        system: A DescriptorSystem for interacting with external resources
         """
         return cls(system=system, **json_data)
 
-    # ================================= XML PARSING ====================================
+    # ================================= XML PARSING ============================
     @staticmethod
     def load_from_xml(xml_data,
             system,
@@ -487,24 +542,33 @@ class ModuleSystem(object):
     '''
     def __init__(self, ajax_url, track_function,
                  get_module, render_template, replace_urls,
-                 user=None, filestore=None, debug=False, xqueue_callback_url=None):
+                 user=None, filestore=None, debug=False,
+                 xqueue_callback_url=None):
         '''
         Create a closure around the system environment.
 
         ajax_url - the url where ajax calls to the encapsulating module go.
+
         track_function - function of (event_type, event), intended for logging
                          or otherwise tracking the event.
                          TODO: Not used, and has inconsistent args in different
                          files.  Update or remove.
+
         get_module - function that takes (location) and returns a corresponding
-                          module instance object.
-        render_template - a function that takes (template_file, context), and returns
-                          rendered html.
-        user - The user to base the random number generator seed off of for this request
-        filestore - A filestore ojbect.  Defaults to an instance of OSFS based at
-                    settings.DATA_DIR.
+                         module instance object.
+
+        render_template - a function that takes (template_file, context), and
+                         returns rendered html.
+
+        user - The user to base the random number generator seed off of for this
+                         request
+
+        filestore - A filestore ojbect.  Defaults to an instance of OSFS based
+                         at settings.DATA_DIR.
+
         replace_urls - TEMPORARY - A function like static_replace.replace_urls
-            that capa_module can use to fix up the static urls in ajax results.
+                         that capa_module can use to fix up the static urls in
+                         ajax results.
         '''
         self.ajax_url = ajax_url
         self.xqueue_callback_url = xqueue_callback_url
@@ -529,4 +593,3 @@ class ModuleSystem(object):
 
     def __str__(self):
         return str(self.__dict__)
-

common/lib/xmodule/xmodule/xml_module.py

@@ -13,13 +13,19 @@ log = logging.getLogger(__name__)
 # TODO (cpennington): This was implemented in an attempt to improve performance,
 # but the actual improvement wasn't measured (and it was implemented late at night).
 # We should check if it hurts, and whether there's a better way of doing lazy loading
+
 class LazyLoadingDict(MutableMapping):
     """
-    A dictionary object that lazily loads it's contents from a provided
-    function on reads (of members that haven't already been set)
+    A dictionary object that lazily loads its contents from a provided
+    function on reads (of members that haven't already been set).
     """
 
     def __init__(self, loader):
+        '''
+        On the first read from this dictionary, it will call loader() to
+        populate its contents.  loader() must return something dict-like. Any
+        elements set before the first read will be preserved.
+        '''
         self._contents = {}
         self._loaded = False
         self._loader = loader
@@ -70,10 +76,12 @@ _AttrMapBase = namedtuple('_AttrMap', 'metadata_key to_metadata from_metadata')
 
 class AttrMap(_AttrMapBase):
     """
-    A class that specifies a metadata_key, a function to transform an xml attribute to be placed in that key,
-    and to transform that key value
+    A class that specifies a metadata_key, a function to transform an xml
+    attribute to be placed in that key, and to transform that key value
     """
-    def __new__(_cls, metadata_key, to_metadata=lambda x: x, from_metadata=lambda x: x):
+    def __new__(_cls, metadata_key,
+                to_metadata=lambda x: x,
+                from_metadata=lambda x: x):
         return _AttrMapBase.__new__(_cls, metadata_key, to_metadata, from_metadata)
 
 
@@ -93,7 +101,9 @@ class XmlDescriptor(XModuleDescriptor):
     # A dictionary mapping xml attribute names to functions of the value
     # that return the metadata key and value
     xml_attribute_map = {
-        'graded': AttrMap('graded', lambda val: val == 'true', lambda val: str(val).lower()),
+        'graded': AttrMap('graded',
+                          lambda val: val == 'true',
+                          lambda val: str(val).lower()),
         'name': AttrMap('display_name'),
     }
 
@@ -105,12 +115,14 @@ class XmlDescriptor(XModuleDescriptor):
 
         xml_object: An etree Element
         """
-        raise NotImplementedError("%s does not implement definition_from_xml" % cls.__name__)
+        raise NotImplementedError(
+            "%s does not implement definition_from_xml" % cls.__name__)
 
     @classmethod
     def clean_metadata_from_xml(cls, xml_object):
         """
-        Remove any attribute named in self.metadata_attributes from the supplied xml_object
+        Remove any attribute named in cls.metadata_attributes from the supplied
+        xml_object
         """
         for attr in cls.metadata_attributes:
             if xml_object.get(attr) is not None:
@@ -134,7 +146,7 @@ class XmlDescriptor(XModuleDescriptor):
 
         xml_data: A string of xml that will be translated into data and children for
             this module
-        system: An XModuleSystem for interacting with external resources
+        system: A DescriptorSystem for interacting with external resources
         org and course are optional strings that will be used in the generated modules
             url identifiers
         """
@@ -157,6 +169,7 @@ class XmlDescriptor(XModuleDescriptor):
             else:
                 filepath = cls._format_filepath(xml_object.tag, filename)
 
+                # VS[compat]
                 # TODO (cpennington): If the file doesn't exist at the right path,
                 # give the class a chance to fix it up. The file will be written out again
                 # in the correct format.
@@ -243,4 +256,5 @@ class XmlDescriptor(XModuleDescriptor):
         """
         Return a new etree Element object created from this modules definition.
         """
-        raise NotImplementedError("%s does not implement definition_to_xml" % self.__class__.__name__)
+        raise NotImplementedError(
+            "%s does not implement definition_to_xml" % self.__class__.__name__)