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

#7_game_2.py
from random import * 
 
def main():
    printIntro()#介绍程序信息
    probA,probB,n = getInputs()#输入参数
    winsA, winsB = simNGames(n,probA,probB)#获胜场数
    PrintSummary(winsA, winsB)
 
def printIntro():
    print('This program simulates a game between two')
    print('There are two players, A and B')
    print('Probability(a number between 0 and 1)is used')
 
def getInputs():
    a = eval(input('What is the prob.player A wins?'))#eval()将str转换为数字型
    b = eval(input('What is the prob.player B wins?'))
    n = eval(input('How many games to simulate?'))
    return a,b,n
 
def simNGames(n,probA,probB):
    winsA = 0
    winsB = 0
    for i in range(n):
        scoreA,scoreB = simOneGame(probA,probB)#得分情况
        if scoreA >scoreB:
            winsA = winsA + 1
        else:
            winsB = winsB + 1
    return winsA,winsB
def simOneGame(probA,probB):
    scoreA = 0
    scoreB = 0
    serving = "A"#开始循环的初始标志
    while not gameOver(scoreA,scoreB):
        if serving == "A":
            if random() < probA:
                scoreA = scoreA + 1
            else:
                serving = "B"
        else:
            if random() < probB:
                scoreB = scoreB + 1
            else:
                serving = "A"
    return scoreA,scoreB
 
def gameOver(a,b):#循环结束的标志
    return a==15 or b==15
 
def PrintSummary(winsA, winsB):
    n = winsA + winsB
    print('
Games simulated:%d'%n)
    print('Wins for A:{0}({1:0.1%})'.format(winsA,winsA/n))
    print('Wins for B:{0}({1:0.1%})'.format(winsB,winsB/n))
 
if __name__ == '__main__':
    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

import random

def onegame(probA,probB):
        scoreA=0
        scoreB=0
        mark="A"
        while mark=="A":
                a=random.random()
                b=random.random()
                a=a*probA
                b=b*probB
                if a>b:
                        scoreA+=1
                else:
                        scoreB+=1
                if scoreA==15 or scoreB==15:
                        mark="B"
        return scoreA,scoreB

def Ngame(n,probA,probB):
        numA=0
        numB=0
        for i in range(n):
                scoreA,scoreB=onegame(probA,probB)
                if scoreA>scoreB:
                        numA+=1
                else:
                        numB+=1
        return numA,numB
                


def main():
        probA=eval(input("probA is :"))
        probB=eval(input("probB is :"))
        n=eval(input("num is :"))

        numA,numB=Ngame(n,probA,probB)
        print('Games simulated:%d'%n)
        print('Wins for A:{0}({1:0.1%})'.format(numA,numA/n))
        print('Wins for B:{0}({1:0.1%})'.format(numB,numB/n))

if __name__ == "__main__":
    main()