price_fraction.py

"""
http://rosettacode.org/wiki/Price_fraction

A friend of mine runs a pharmacy.
He has a specialised function in his Dispensary application which
receives a decimal value of currency and replaces it to a standard value.
This value is regulated by a government department.

Task: Given a floating point value between 0.00 and 1.00,
rescale according to the following table:

>=  0.00  <  0.06  :=  0.10
>=  0.06  <  0.11  :=  0.18
>=  0.11  <  0.16  :=  0.26
>=  0.16  <  0.21  :=  0.32
>=  0.21  <  0.26  :=  0.38
>=  0.26  <  0.31  :=  0.44
>=  0.31  <  0.36  :=  0.50
>=  0.36  <  0.41  :=  0.54
>=  0.41  <  0.46  :=  0.58
>=  0.46  <  0.51  :=  0.62
>=  0.51  <  0.56  :=  0.66
>=  0.56  <  0.61  :=  0.70
>=  0.61  <  0.66  :=  0.74
>=  0.66  <  0.71  :=  0.78
>=  0.71  <  0.76  :=  0.82
>=  0.76  <  0.81  :=  0.86
>=  0.81  <  0.86  :=  0.90
>=  0.86  <  0.91  :=  0.94
>=  0.91  <  0.96  :=  0.98
>=  0.96  <  1.01  :=  1.00
"""


class PriceRescaler(object):
    def __init__(self, table):
        self.upperBoundPriceTuples = self.transform(table)

    def transform(self, table):
        pairs = []
        for line in table.splitlines():
            interval, result = line.split(":=")
            upperBound = interval.split('<')[1]
            pairs.append((float(upperBound), float(result)))
        return pairs

    def rescale(self, price):
        for upperBound, result in self.upperBoundPriceTuples:
            if price < upperBound:
                return result


if __name__ == '__main__':
    pt = PriceRescaler(__doc__.split("following table:")[-1].strip())
    for n in range(101):
        price = n / 100.0
        print("%.2f -> %.2f" % (price, pt.rescale(price)))