Programming performance/hay.steve Python

• Implementation time: 2 hours.
• Experience: 3 days.

Code

<code-python> from heapq import heappush, heappop, nsmallest

print "Implementation time: 2 hours. Python experience: 3 days."

filename = "gspc.txt"

days = []

for f in open(filename):

       if f[0] == '#':
               continue
       linelist = f.split(' ')
       heappush( days, linelist )

cash = 10000

previousClose = -1.0

currentClose = 0

shares = []

beginningBalance = cash

print "Beginning Balance:", cash while days != []:

       day = heappop( days )
       i = day[0]
       currentClose = float( day[4] )

       if previousClose != -1.0:
               percentGain = ( currentClose - previousClose ) / previousClose
               if percentGain < -0.03:
                       numShares = 0.1 * cash / currentClose
                       heappush( shares, (currentClose, numShares) )
                       cash = 0.9 * cash
                       print "On", i, ", bought" , numShares , "shares at" , currentClose , "."

               else :
                       while shares != [] and nsmallest(1, shares)[0][0] <= currentClose / 1.06:
                               sell = heappop( shares )
                               cash += sell[1] * currentClose
                               print "On", i, "sold" , sell[1] , "shares at" , currentClose , "."

       previousClose = currentClose

while shares != []:

       sell = heappop( shares )
       cash += sell[1] * currentClose
       print "Sold" , sell[1] , "shares at" , currentClose , "."

print "Beginning balance:", beginningBalance

print "Ending balance:", cash

print "Percent Gain:", (cash-beginningBalance)/beginningBalance*100, "%." </code-python>

--Hay.steve 01:53, 8 March 2007 (UTC)