Django: Round price to 2 decimals

roundTwoDecimals.py

@property
def update_price(self):
    """
    Return a rounded price using the quantity and rate.

    This utilizes the Decimal object to get around the strange
    rounding behavior in Python with Base 10. The logic converts
    both operands to Decimal objects, multiplies them, then
    performs a ROUND_UP method using 2 decimal places.
    """
    from decimal import *

    q = Decimal(self.quantity)
    r = Decimal(self.rate)

    if q > 0.00 and r > 0.00:
        p = q * r
        return p.quantize(Decimal('.01'), rounding=ROUND_UP)
    else:
        return 0.00

'float' object has no attribute 'quantize'