Reading Event with Duration causes exception

[meera]

I printed the component def create_event(component):

The Event in ical file is

BEGIN:VEVENT
UID:10613
DTSTAMP:20180223T130634Z
SUMMARY:A great event Day
CLASS:PUBLIC
STATUS:CONFIRMED
PRIORITY:0
SEQUENCE:0
DTSTART:20180126
DURATION:P1D
LAST-MODIFIED:20180102T224058Z
TRANSP:OPAQUE
END:VEVENT

Component is
VEVENT({'DTSTART': <icalendar.prop.vDDDTypes object at 0x10b9e3240>, 'SUMMARY': vText('b'A great event Day ''), 'DURATION': <icalendar.prop.vDDDTypes object at 0x10b9ba588>, 'STATUS': vText('b'CONFIRMED''), 'PRIORITY': 0, 'LAST-MODIFIED': <icalendar.prop.vDDDTypes object at 0x10b9bacc0>, 'TRANSP': vText('b'OPAQUE''), 'UID': vText('b'10613''), 'SEQUENCE': 0, 'DTSTAMP': <icalendar.prop.vDDDTypes object at 0x10b9baf98>, 'CLASS': vText('b'PUBLIC'')})
Traceback (most recent call last):
File "/Users/anaconda2/envs_env/bin/flask", line 11, in
sys.exit(main())
File "/Users/anaconda2/envs_env/lib/python3.5/site-packages/flask/cli.py", line 513, in main
cli.main(args=args, prog_name=name)
File "/Users/anaconda2/envs_env/lib/python3.5/site-packages/flask/cli.py", line 380, in main
return AppGroup.main(self, *args, **kwargs)
File "/Users/anaconda2/envs_env/lib/python3.5/site-packages/click/core.py", line 697, in main
rv = self.invoke(ctx)
File "/Users/anaconda2/envs_env/lib/python3.5/site-packages/click/core.py", line 1066, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/Users/anaconda2/envs_env/lib/python3.5/site-packages/click/core.py", line 895, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/Users/anaconda2/envs_env/lib/python3.5/site-packages/click/core.py", line 535, in invoke
return callback(*args, **kwargs)
File "/Users/anaconda2/envs_env/lib/python3.5/site-packages/click/decorators.py", line 17, in new_func
return f(get_current_context(), *args, **kwargs)
File "/Users/anaconda2/envs_env/lib/python3.5/site-packages/flask/cli.py", line 257, in decorator
return __ctx.invoke(f, *args, **kwargs)
File "/Users/anaconda2/envs_env/lib/python3.5/site-packages/click/core.py", line 535, in invoke
return callback(*args, **kwargs)
File "/Users/populate_events.py", line 46, in populate_events
all_events = events(url=school.calender_url)
File "/Users/icalevents/icalevents/icalevents.py", line 40, in events
found_events += parse_events(content, start=start, end=end)
File "/Users/icalevents/icalevents/icalparser.py", line 257, in parse_events
e = create_event(component)
File "/Users/icalevents/icalevents/icalparser.py", line 155, in create_event
event_end = normalize(component.get('dtend').dt)
AttributeError: 'NoneType' object has no attribute 'dt'