python——体育竞技

一、体育竞技分析
基本规则
两个球员，交替用球拍击球
发球权，回合
未能进行一次击打回合结束
首先达到15分赢得比赛

1、自顶向下的设计

 1 #7_game_2.py
 2 from random import * 
 3  
 4 def main():
 5     printIntro()#介绍程序信息
 6     probA,probB,n = getInputs()#输入参数
 7     winsA, winsB = simNGames(n,probA,probB)#获胜场数
 8     PrintSummary(winsA, winsB)
 9  
10 def printIntro():
11     print('This program simulates a game between two')
12     print('There are two players, A and B')
13     print('Probability(a number between 0 and 1)is used')
14  
15 def getInputs():
16     a = eval(input('What is the prob.player A wins?'))#eval()将str转换为数字型
17     b = eval(input('What is the prob.player B wins?'))
18     n = eval(input('How many games to simulate?'))
19     return a,b,n
20  
21 def simNGames(n,probA,probB):
22     winsA = 0
23     winsB = 0
24     for i in range(n):
25         scoreA,scoreB = simOneGame(probA,probB)#得分情况
26         if scoreA >scoreB:
27             winsA = winsA + 1
28         else:
29             winsB = winsB + 1
30     return winsA,winsB
31 def simOneGame(probA,probB):
32     scoreA = 0
33     scoreB = 0
34     serving = "A"#开始循环的初始标志
35     while not gameOver(scoreA,scoreB):
36         if serving == "A":
37             if random() < probA:
38                 scoreA = scoreA + 1
39             else:
40                 serving = "B"
41         else:
42             if random() < probB:
43                 scoreB = scoreB + 1
44             else:
45                 serving = "A"
46     return scoreA,scoreB
47  
48 def gameOver(a,b):#循环结束的标志
49     return a==15 or b==15
50  
51 def PrintSummary(winsA, winsB):
52     n = winsA + winsB
53     print('
Games simulated:%d'%n)
54     print('Wins for A:{0}({1:0.1%})'.format(winsA,winsA/n))
55     print('Wins for B:{0}({1:0.1%})'.format(winsB,winsB/n))
56  
57 if __name__ == '__main__':
58     main()

载入程序，对各个函数分别测试

整个过程反映了，由顶至下的设计和由下至上的运行，整个编程的思路就是这样。

（2）程序简化

 1 import random
 2 
 3 def onegame(probA,probB):
 4         scoreA=0
 5         scoreB=0
 6         mark="A"
 7         while mark=="A":
 8                 a=random.random()
 9                 b=random.random()
10                 a=a*probA
11                 b=b*probB
12                 if a>b:
13                         scoreA+=1
14                 else:
15                         scoreB+=1
16                 if scoreA==15 or scoreB==15:
17                         mark="B"
18         return scoreA,scoreB
19 
20 def Ngame(n,probA,probB):
21         numA=0
22         numB=0
23         for i in range(n):
24                 scoreA,scoreB=onegame(probA,probB)
25                 if scoreA>scoreB:
26                         numA+=1
27                 else:
28                         numB+=1
29         return numA,numB
30                 
31 
32 
33 def main():
34         probA=eval(input("probA is :"))
35         probB=eval(input("probB is :"))
36         n=eval(input("num is :"))
37 
38         numA,numB=Ngame(n,probA,probB)
39         print('Games simulated:%d'%n)
40         print('Wins for A:{0}({1:0.1%})'.format(numA,numA/n))
41         print('Wins for B:{0}({1:0.1%})'.format(numB,numB/n))
42 
43 if __name__ == "__main__":
44     main()