rounding question

[buran]

But you don't want decimals on your report (or in your accounting system for that matter).

Actually I do want decimals in my accounting system, up to the last cent :-) And in some cases like interest/coupon accrual rounding is only at the end of the accrual period


int will always truncate downwards, when argument is float:

For floating point numbers, this truncates towards zero.

>>> int(5.99)
5

In your example with 5.50 + 0.50 it was the same - truncated toward 6

>>> d = 5.50 + 0.50
>>> d
6.0
>>> int(d)
6

"random" so to speak.

Nothing random here

When working with money, better work with decimal.Decimal to avoid floating-point arithmetic surprises.