Calculate the total time based on the summary and time of iCalendar Events

semester_report

from icalendar import Calendar
from datetime import timedelta
from itertools import groupby
from operator import itemgetter


def calculate_time(event):
    start = event['DTSTART'].dt
    end = event['DTEND'].dt
    return end - start


def lecturize(event):
    summary = str(event['SUMMARY'])
    for lecture in lectures:
        if lecture in summary:
            return lecture


def time_per_lecture(events):
    sorted_events = sorted(events, key=itemgetter(0))
    for key, group in groupby(sorted_events, itemgetter(0)):
        yield (key, sum(map(itemgetter(1), group), timedelta()))

lectures = ['An1I', 'Math1I', 'Bsys1', 'CN1', 'EnglHTw', 'Prog1', 'ICTh']
file = open('examtime_export.ics', 'rb')
cal = Calendar.from_ical(file.read())
events = [(lecturize(e), calculate_time(e)) for e in cal.walk('vevent')]

used_time = dict(time_per_lecture(events))
total_time = sum(used_time.values(), timedelta())

for lecture, time in used_time.items():
    print('{}\t{}h'.format(lecture, time.total_seconds() / 3600))

print('=============')
print('TOTAL\t{}h'.format(total_time.total_seconds() / 3600))

Dear Lukas,

Thanks for your Python script. Congrats for the nice style. I used it for checking next year schedules at my school, ENS Rennes in Brittany, France.

I encountered a problem. If the schedule does not contains the lectures only, then lecturize my return None, so that the sorting phase of time_per_lecture fails.

You might wish to add a filter to remove all None tuples from the events list. Here is my solution, although using filter would probably be more elegant.

events = [(lecturize(e), calculate_time(e)) for e in cal.walk('vevent')]
events = [e for e in events if e[0] != None]

Another possibility is to filter out at the construction of the events list.

Best regards,

Luc.

Perhaps it should be added such codes:
import sys
reload(sys)
sys.setdefaultencoding('utf8')

Hi Lukas,,

def calculate_time(event): start = event['DTSTART'].dt end = event['DTEND'].dt return start

In the code snippet above, event['DTEND'].dt throws a key error. Do you know if the module has changed since you wrote the code?