[Quantlib-users] How to use CallabilitySchedule class properly

[Christofer B. <bog...@gm...>]

Hi,

I was looking at an example in -
http://gouthamanbalaraman.com/blog/callable-bond-quantlib-python.html

However I failed to understand how the call option schedule is
constructed in below snippet?

callability_schedule = ql.CallabilitySchedule()
call_price = 100.0
call_date = ql.Date(15,ql.September,2016);
null_calendar = ql.NullCalendar();
for i in range(0,24):
    callability_price  = ql.CallabilityPrice(
        call_price, ql.CallabilityPrice.Clean)
    callability_schedule.append(
            ql.Callability(callability_price,
                           ql.Callability.Call,
                           call_date))

    call_date = null_calendar.advance(call_date, 3, ql.Months);

Why I need to run a loop as "for i in range(0,24)" to create a
singleton schedule at  ql.Date(15,ql.September,2016)?

If I had only 2 callability schedules like
ql.Date(15,ql.September,2016) & ql.Date(15,ql.October,2016) within the
lifetime of the underlying Bond then how should I proceed?

Your help will be very much appreciated.

Thanks,