[FIXED] How to round a Python Decimal to 2 decimal places?

Issue

I've got a python Decimal (a currency amount) which I want to round to two decimal places. I tried doing this using the regular round() function. Unfortunately, this returns a float, which makes it unreliable to continue with:

>>> from decimal import Decimal
>>> a = Decimal('1.23456789')
>>> type(round(a, 2))
<type 'float'>

in the decimal module, I see a couple things in relation to rounding:

• ROUND_05UP
• ROUND_CEILING
• ROUND_DOWN
• ROUND_FLOOR
• ROUND_HALF_DOWN
• ROUND_HALF_EVEN
• ROUND_HALF_UP
• ROUND_UP
• Rounded

I think that none of these actually give what I want though (or am I wrong here?).

So my question: does anybody know how I can reliably round a Python Decimal to 2 decimal places so that I have a Decimal to continue with? All tips are welcome!

Solution

Since Python 3.3 you can use round() with a Decimal and it will return you a Decimal:

>>> from decimal import Decimal
>>> round(Decimal('3.14159265359'), 3)
Decimal('3.142')

See details in this answer.

Answered By - ericbn

Answer Checked By - Cary Denson (PHPFixing Admin)