script1.py

def get_event_date(event):
    return event.date
def current_user(events):
    events.sort(key=get_event_date)
    machines = {}
    for event in events:
        if event.machine not in machines:
            machines[event.machine]=set()
        if event.type =="login":
            machines[event.machine].add(event.user)
        elif event.type == "logout":
            machines[event.machine].remove(event.user)
    return machines
def generate_report(machines):
    for machine,users in machines.items():
        if len(users) > 0:
            user_list = ", ".join(users)
            print("{}: {}".format(machine,user_list))
    
# .........class..........
class Event:
    def __init__(self,event_date,event_type,machine_name,user):
        self.date = event_date
        self.type = event_type
        self.machine = machine_name
        self.user = user

# .......list of Events.....
events = [
    Event('2020-01-21 12:45:56', 'login', 'myworkstation.local', 'jordan'),
    Event('2020-01-22 15:53:42', 'logout', 'webserver.local', 'jordan'),
    Event('2020-01-21 18:53:21', 'login', 'webserver.local', 'lane'),
    Event('2020-01-22 10:25:34', 'logout', 'myworkstation.local', 'jordan'),
    Event('2020-01-21 08:20:01', 'login', 'webserver.local', 'jordan'),
    Event('2020-01-23 11:24:35', 'login', 'mailserver.local', 'chris'),
]
users = current_user(events)
# print(users)
generate_report(users)