商城的打鱼游戏——最终平均成交价计算
鉴于同事的疑惑
import random
# import pylab
def judge(discountPrice, energy, shell, fish):
'''After User fired the shell, judge the result.'''
if type(fish) == str:
probabiliity = shell/eval(fish)
capture = random.random() < probabiliity
if capture: energy = energy + eval(fish)
else:
probabiliity = shell/fish
capture = random.random() < probabiliity
if capture: discountPrice = discountPrice - fish
return discountPrice,energy
def userBehavior(price, lowestDiscount, energy=0):
'''Simulate teh User firing shells. '''
discountPrice = price
energy = lowestDiscount if energy == 0 else energy
shell = lowestDiscount/20
discountFishes = [i*discountPrice/10 for i in range(1, 10)]
energyFishes = ['2*shell', '3*shell', '5*shell', '7*shell', '8*shell', '10*shell', '15*shell', '20*shell', '30*shell']
fishes = discountFishes + energyFishes
fishNum = random.choice([1,1,1,1,2,2,3])
while energy >= shell and discountPrice > lowestDiscount:
energy = energy - shell
fish = random.choice(fishes)
discountPrice, energy = judge(discountPrice, energy, shell, fish)
return discountPrice
def summary(price,lowestDiscount,frequency = 1000):
'''repeat fishing 'frequency' times'''
discountPrices = []
for k in range(frequency):
discountPrice = (userBehavior(price, lowestDiscount))
discountPrices.append(discountPrice)
print('平均折扣价 :', sum(discountPrices)/len(discountPrices), ' 平均获得折扣 :', round(sum(discountPrices)/len(discountPrices)/price, 2))
print('未获得折扣次数 :', discountPrices.count(price))
# pylab.plot(discountPrices)
# pylab.title('discountPrice,%d time' % frequency)
# pylab.xlabel('appear')
# pylab.ylabel('discountPrice')
summary(100, 10, frequency=1000)