Get companies that haven't signed up but visited our website

from exhibitors.models import Exhibitor
from fair.models import Fair
import datetime

from companies.models import SignupLog

signup_logs = SignupLog.objects.filter()

fair = Fair.objects.filter(current=True)

exhibitors = Exhibitor.objects.filter(fair=fair)
exhibitor_set = set()

for exhibitor in exhibitors:
    exhibitor_set.add(str(exhibitor.company).upper())

signup_logs = SignupLog.objects.filter()

for signup_log in signup_logs:
    start_date = datetime.datetime(2021, 6, 22, 23, 59)
    end_date = datetime.datetime(2021, 9, 8, 18, 50)
    timestamp = signup_log.timestamp

    company = signup_log.company
    have_not_signed = str(company).upper() not in exhibitor_set

    if start_date < timestamp and timestamp < end_date and have_not_signed:
        print()
        print(f"--- {company} ---")
        print(f"Person: {signup_log.company_contact}")
        print(f"Visited: {timestamp}")
        print("---")