这本书的上半部分你打印了一些东西，而且调用了函数，不过一切都是直线式进行的。你的脚本从最上面一行开始，一路运行到结束，但其中并没有决定程序流向的分支点。现在你已经学了 if, else, 和 elif ，你就可以开始创建包含条件判断的脚本了。
上一个脚本中你写了一系列的简单提问测试。这节的脚本中，你将需要向用户提问，依据用户的答案来做出决定。把脚本写下来，多多鼓捣一阵子，看看它的工作原理是什么。
1 print "You enter a dark room with two doors. Do you go through door #1 or door #2?" 2 3 door = raw_input("> ") 4 5 if door == "1": 6 print "There's a giant bear here eating a cheese cake. What do you do?" 7 print "1. Take the cake." 8 print "2. Scream at the bear." 9 10 bear = raw_input("> ") 11 12 if bear == "1": 13 print "The bear eats your face off. Good job!" 14 elif bear == "2": 15 print "The bear eats your legs off. Good job!" 16 else: 17 print "Well, doing %s is probably better. Bear runs away." % bear 18 19 elif door == "2": 20 print "You stare into the endless abyss at Cthulhu's retina." 21 print "1. Blueberries." 22 print "2. Yellow jacket clothespins." 23 print "3. Understanding revolvers yelling melodies." 24 25 insanity = raw_input("> ") 26 27 if insanity == "1" or insanity == "2": 28 print "Your body survives powered by a mind of jello. Good job!" 29 else: 30 print "The insanity rots your eyes into a pool of muck. Good job!" 31 32 else: 33 print "You stumble around and fall on a knife and die. Good job!"