Simple script to get google calendar events using the Google API

gcal_events.py

#!/usr/bin/env python

import datetime
import pathlib

ROOT = pathlib.Path(__file__).resolve().parent

#List of calendar names to get events from
#if empty, just take all calendars
GOOGLE_CALENDARS = [
]

from googleapiclient.discovery import build
from google_auth_oauthlib.flow import InstalledAppFlow
from google.auth.transport.requests import Request
from google.oauth2.credentials import Credentials


# If modifying these scopes, delete the file token.json.
GOOGLE_SCOPES = ['https://www.googleapis.com/auth/calendar.readonly']


def get_calendar_data(date):
    """Basic usage of the Google Calendar API, get events of the date from either all calendars or the ones listed in `GOOGLE_CALENDARS`.
    """

    creds = None
    # The file token.json stores the user's access and refresh tokens, and is
    # created automatically when the authorization flow completes for the first
    # time.
    token_file = ROOT / 'token.json'
    credential_file = ROOT / 'credentials.json'

    if token_file.is_file():
        creds = Credentials.from_authorized_user_file(str(token_file.resolve()), GOOGLE_SCOPES)
    # If there are no (valid) credentials available, let the user log in.
    if not creds or not creds.valid:
        if creds and creds.expired and creds.refresh_token:
            creds.refresh(Request())
        else:
            flow = InstalledAppFlow.from_client_secrets_file(
                str(credential_file.resolve()), GOOGLE_SCOPES)
            creds = flow.run_local_server(port=0)
        # Save the credentials for the next run
        with open(str(token_file.resolve()), 'w') as token:
            token.write(creds.to_json())

    service = build('calendar', 'v3', credentials=creds)

    # Call the Calendar API
    # 'Z' indicates UTC time
    start_dt = datetime.datetime(date.year, date.month, date.day, 0, 0, 0)
    start = start_dt.isoformat() + 'Z'
    stop = (start_dt + datetime.timedelta(days=1)).isoformat() + 'Z'

    calendars = []
    
    # Get all the calendar id's and names the user has access too
    page_token = None
    while True:
        calendar_list = service.calendarList().list(pageToken=page_token).execute()
        for calendar_list_entry in calendar_list['items']:
            calendars.append((calendar_list_entry['id'], calendar_list_entry['summary']))
        page_token = calendar_list.get('nextPageToken')
        if not page_token:
            break

    #Use the `events` service on each calendar to get the events.
    events = []
    for calendar, summary in calendars:
        if summary not in GOOGLE_CALENDARS and len(GOOGLE_CALENDARS) > 0:
            continue
        events_result = service.events().list(
            calendarId=calendar, 
            timeMin=start,
            timeMax=stop,
            maxResults=None, 
            singleEvents=True,
            orderBy='startTime',
        ).execute()

        cal_events = events_result.get('items', [])
        for x in cal_events:
            x['calendar_summary'] = summary

        events += cal_events

    #do some sorting
    for ev in events:
        start = ev['start'].get('dateTime', ev['start'].get('date'))
        start_dt = datetime.datetime.fromisoformat(start)
        start_dt = start_dt.replace(tzinfo=datetime.datetime.now().astimezone().tzinfo)
        ev['_sort_date'] = start_dt

    events.sort(key=lambda ev: ev['_sort_date'])
    return events


if __name__=='__main__':
    events = get_calendar_data(datetime.datetime.today())
    for event in events:
        print(event["summary"])