Parsing files (ics / icalendar) using Python

Question

I have a .ics file in the following format. What is the best way to take it apart? I need to get a summary, description and time for each of the entries.

BEGIN:VCALENDAR X-LOTUS-CHARSET:UTF-8 VERSION:2.0 PRODID:-//Lotus Development Corporation//NONSGML Notes 8.0//EN METHOD:PUBLISH BEGIN:VTIMEZONE TZID:India BEGIN:STANDARD DTSTART:19500101T020000 TZOFFSETFROM:+0530 TZOFFSETTO:+0530 END:STANDARD END:VTIMEZONE BEGIN:VEVENT DTSTART;TZID="India":20100615T111500 DTEND;TZID="India":20100615T121500 TRANSP:OPAQUE DTSTAMP:20100713T071035Z CLASS:PUBLIC DESCRIPTION:Emails\nDarlene\n Murphy\nDr. Ferri\n UID:12D3901F0AD9E83E65257743001F2C9A-Lotus_Notes_Generated X-LOTUS-UPDATE-SEQ:1 X-LOTUS-UPDATE-WISL:$S:1;$L:1;$B:1;$R:1;$E:1;$W:1;$O:1;$M:1 X-LOTUS-NOTESVERSION:2 X-LOTUS-APPTTYPE:0 X-LOTUS-CHILD_UID:12D3901F0AD9E83E65257743001F2C9A END:VEVENT BEGIN:VEVENT DTSTART;TZID="India":20100628T130000 DTEND;TZID="India":20100628T133000 TRANSP:OPAQUE DTSTAMP:20100628T055408Z CLASS:PUBLIC DESCRIPTION: SUMMARY:smart energy management LOCATION:8778/92050462 UID:07F96A3F1C9547366525775000203D96-Lotus_Notes_Generated X-LOTUS-UPDATE-SEQ:1 X-LOTUS-UPDATE-WISL:$S:1;$L:1;$B:1;$R:1;$E:1;$W:1;$O:1;$M:1 X-LOTUS-NOTESVERSION:2 X-LOTUS-NOTICETYPE:A X-LOTUS-APPTTYPE:3 X-LOTUS-CHILD_UID:07F96A3F1C9547366525775000203D96 END:VEVENT BEGIN:VEVENT DTSTART;TZID="India":20100629T110000 DTEND;TZID="India":20100629T120000 TRANSP:OPAQUE DTSTAMP:20100713T071037Z CLASS:PUBLIC SUMMARY:meeting UID:6011DDDD659E49D765257751001D2B4B-Lotus_Notes_Generated X-LOTUS-UPDATE-SEQ:1 X-LOTUS-UPDATE-WISL:$S:1;$L:1;$B:1;$R:1;$E:1;$W:1;$O:1;$M:1 X-LOTUS-NOTESVERSION:2 X-LOTUS-APPTTYPE:0 X-LOTUS-CHILD_UID:6011DDDD659E49D765257751001D2B4B END:VEVENT 

Answer 1

The icalendar package looks beautiful.

For example, to write a file:

 from icalendar import Calendar, Event from datetime import datetime from pytz import UTC # timezone cal = Calendar() cal.add('prodid', '-//My calendar product//mxm.dk//') cal.add('version', '2.0') event = Event() event.add('summary', 'Python meeting about calendaring') event.add('dtstart', datetime(2005,4,4,8,0,0,tzinfo=UTC)) event.add('dtend', datetime(2005,4,4,10,0,0,tzinfo=UTC)) event.add('dtstamp', datetime(2005,4,4,0,10,0,tzinfo=UTC)) event['uid'] = '20050115T101010/[e-mail]' event.add('priority', 5) cal.add_component(event) f = open('example.ics', 'wb') f.write(cal.to_ical()) f.close() 

Tadaaaa, you get this file:

 BEGIN:VCALENDAR PRODID:-//My calendar product//mxm.dk// VERSION:2.0 BEGIN:VEVENT DTEND;VALUE=DATE:20050404T100000Z DTSTAMP;VALUE=DATE:20050404T001000Z DTSTART;VALUE=DATE:20050404T080000Z PRIORITY:5 SUMMARY:Python meeting about calendaring UID:20050115T101010/[e-mail] END:VEVENT END:VCALENDAR 

But what lies in this file?

 g = open('example.ics','rb') gcal = Calendar.from_ical(g.read()) for component in gcal.walk(): print component.name g.close() 

You can easily see this:

 >>> VCALENDAR VEVENT >>> 

How about parsing event data:

 g = open('example.ics','rb') gcal = Calendar.from_ical(g.read()) for component in gcal.walk(): if component.name == "VEVENT": print(component.get('summary')) print(component.get('dtstart')) print(component.get('dtend')) print(component.get('dtstamp')) g.close() 

Now you get:

 >>> Python meeting about calendaring 20050404T080000Z 20050404T100000Z 20050404T001000Z >>> 

Answer 2

Perhaps you can also use the vobject module for this: http://pypi.python.org/pypi/vobject

If you have a sample.ics file, you can read its contents, for example:

 # read the data from the file data = open("sample.ics").read() # parse the top-level event with vobject cal = vobject.readOne(data) # Get Summary print 'Summary: ', cal.vevent.summary.valueRepr() # Get Description print 'Description: ', cal.vevent.description.valueRepr() # Get Time print 'Time (as a datetime object): ', cal.vevent.dtstart.value print 'Time (as a string): ', cal.vevent.dtstart.valueRepr() 

Answer 3

You can also use this new Python package: http://packages.python.org/pyICSParser/

It parses the file and converts it into a Python array for easy processing.

Answer 4

After four years and understanding the ICS format is a little better, if these were the only fields I needed, I would just use my own string methods:

 import io # Probably not a valid .ics file, but we don't really care for the example # it works fine regardless file = io.StringIO(''' BEGIN:VCALENDAR X-LOTUS-CHARSET:UTF-8 VERSION:2.0 DESCRIPTION:Emails\nDarlene\n Murphy\nDr. Ferri\n SUMMARY:smart energy management LOCATION:8778/92050462 DTSTART;TZID="India":20100629T110000 DTEND;TZID="India":20100629T120000 TRANSP:OPAQUE DTSTAMP:20100713T071037Z CLASS:PUBLIC SUMMARY:meeting UID:6011DDDD659E49D765257751001D2B4B-Lotus_Notes_Generated X-LOTUS-UPDATE-SEQ:1 X-LOTUS-UPDATE-WISL:$S:1;$L:1;$B:1;$R:1;$E:1;$W:1;$O:1;$M:1 X-LOTUS-NOTESVERSION:2 X-LOTUS-APPTTYPE:0 X-LOTUS-CHILD_UID:6011DDDD659E49D765257751001D2B4B END:VEVENT '''.strip()) parsing = False for line in file: field, _, data = line.partition(':') if field in ('SUMMARY', 'DESCRIPTION', 'DTSTAMP'): parsing = True print(field) print('\t'+'\n\t'.join(data.split('\n'))) elif parsing and not data: print('\t'+'\n\t'.join(field.split('\n'))) else: parsing = False 

Saving data and analyzing date and time are left as an exercise for the reader (this is always UTC)

old answer below

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You can use regex:

 import re text = #your text print(re.search("SUMMARY:.*?:", text, re.DOTALL).group()) print(re.search("DESCRIPTION:.*?:", text, re.DOTALL).group()) print(re.search("DTSTAMP:.*:?", text, re.DOTALL).group()) 

I’m sure it’s possible to skip the first and last words, I’m just not sure how to do this with a regular expression. You could do it like this:

 print(' '.join(re.search("SUMMARY:.*?:", text, re.DOTALL).group().replace(':', ' ').split()[1:-1]) 

Answer 5

New in Python; The comments above were very helpful, so I wanted to publish a more complete sample.

 # ics to csv example # dependency: https://pypi.org/project/vobject/ import vobject import csv with open('sample.csv', mode='w') as csv_out: csv_writer = csv.writer(csv_out, delimiter=',', quotechar='"', quoting=csv.QUOTE_MINIMAL) csv_writer.writerow(['WHAT', 'WHO', 'FROM', 'TO', 'DESCRIPTION']) # read the data from the file data = open("sample.ics").read() # iterate through the contents for cal in vobject.readComponents(data): for component in cal.components(): if component.name == "VEVENT": # write to csv csv_writer.writerow([component.summary.valueRepr(),component.attendee.valueRepr(),component.dtstart.valueRepr(),component.dtend.valueRepr(),component.description.valueRepr()]) 

Answer 6

I would parse lines by lines and search for your conditions, then get the index and extract it, as well as the number of X characters (no matter how you think you need). Then parse this much smaller line to get what you need.