models: Don't use != None for date/time values

Dates and times are "true" when used as booleans; None is "false".
So, these values can be used directly.

Author: encukou

naucse/models.py

@@ -305,7 +305,7 @@ def __str__(self):
     date = DataProperty(info, default=None)
 
     def _time(self, key, default_time):
-        if self.date != None and default_time != None:
+        if self.date and default_time:
             return datetime.datetime.combine(self.date, default_time)
         return None
 

naucse/routes.py

@@ -334,12 +334,12 @@ def course_calendar_ics(course):
         abort(404)
     calendar = ics.Calendar()
     for session in course.sessions.values():        
-        if session.start_time == None:
-            start_time = datetime.datetime.combine(session.date, datetime.time())
-            end_time = None
-        else:
+        if session.start_time:
             start_time = session.start_time
             end_time = session.end_time
+        else:
+            start_time = datetime.datetime.combine(session.date, datetime.time())
+            end_time = None
         cal_event = ics.Event(
             name = session.title,
             begin = start_time,

naucse/templates/course.html

@@ -57,7 +57,7 @@ <h4>
                             <div class="calendar-dates">
                                 {{ (course.start_date, course.end_date) | format_date_range }}
                             </div>
-                            {% if course.default_start_time != None  %}
+                            {% if course.default_start_time %}
                                 <div class="default-times">
                                     {{ course.default_start_time }}
                                     –