code critique requested - just 60 lines

[Terrence Brannon]

Hi, I would like some feedback on how you would improve the following
program:
http://www.bitbucket.org/metaperl/ptc_math/src/21979c65074f/payout.py

Basically, using non-strict dictionary keys can lead to bugs, so that
worried me. Also, I'm not sure that my code is as crisp and concise as
it could be. I also did not like the long string representation in the
Scenerio class. It is hard to read and error-prone to code.

Any feedback on how you would've written this differently is welcome,
either by commenting below, or by checking out the repo and checking
it back in!

class Rates:

    def __init__(self, per_click, per_ref_click):
        self.per_click = per_click
        self.per_ref_click = per_ref_click

    def __str__(self):
        return 'per_click: %.2f per_ref_click: %.2f' %
(self.per_click, self.per_ref_click)


ad_rate = 200 # 2 dollars for 100 clicks

# http://code.activestate.com/recipes/278259/
def sumDict(d):
    return reduce(lambda x,y:x+y, d.values())


rates = {}
rates['std']  = Rates(per_click=1,    per_ref_click=0.5)
rates['vip']  = Rates(per_click=1.25, per_ref_click=1.25)

class Scenario:



    def __init__(self, std_clicks, vip_clicks, upline_status):
        self.clicks = {}
        self.payout = {}
        self.ad_rate = 200

        self.clicks['std'] = std_clicks
        self.clicks['vip'] = vip_clicks
        self.upline_status = upline_status

    def calc_profit(self):
        for member_type in rates:
            self.payout[member_type] = self.clicks[member_type] *
rates[member_type].per_click
        if self.upline_status is None:
            self.payout['upline'] = 0
        else:
            self.payout['upline'] = sumDict(self.clicks) *
rates[upline_status].per_ref_click
            #print "rates: %s self.clicks: %d upline payout: %.1f\n" %
(rates[upline_status], sumDict(self.clicks), self.payout['upline'])
        return ad_rate - sumDict(self.payout)


    def __str__(self):
        profit = self.calc_profit()
        return 'upline_status: %s upline_payout: %.1f\n\tstd_clicks:
%d std_payout %.1f vip_clicks: %d vip_payout: %.1f\n\t\tProfit: %.1f
\n' % (self.upline_status, self.payout['upline'], self.clicks['std'],
self.payout['std'], self.clicks['vip'], self.payout['vip'], profit)



scenario = []

for upline_status in [None, 'std', 'vip']:
    for vip_clicks in [0, 25, 50, 75, 100]:
        std_clicks = 100 - vip_clicks
        scenario.append(Scenario(std_clicks, vip_clicks,
upline_status))

# really, we could've printed the objects as they were made, but for
debugging, I kept creation and
# printing as separate steps
for s in scenario:
    print s