练习31--做决定
一 if语句的嵌套
1 在嵌套的 if 语句结构，可以在一个 if... elif... else 结构里面可有另外一个 if... elif... else 结构。
语法：
1 if expression1: 2 statement(s) 3 if expression2: 4 statement(s) 5 elif expression3: 6 statement(s) 7 else 8 statement(s) 9 elif expression4: 10 statement(s) 11 else: 12 statement(s)
if、elif、else可组成一个整体的条件语句，其中：
- if是必须有的；
- elif可以没有，也可以有很多个，每个elif的条件不满足时会进入下一个elif的判断；
- else可以没有，有的话只能有一个，必须在条件语句的最后，且没有逻辑判断语句。
二 代码及运行结果
1 ex31.py
1 print("""You enter a dark room with two doors. 2 Do you go through door #1 or door #2?""") 3 4 door = input(">") 5 6 if door == "1": 7 print("There's a giant bear here eating a cheese cake.") 8 print("What do you do?") 9 print("1. Take the cake.") 10 print("2. Scream at the bear.") 11 12 bear = input(">") 13 14 if bear == "1": 15 print("The bear eats your face off.Good job!") 16 elif bear == "2": 17 print("The bear eats your legs off.Good job!") 18 else: 19 print(f"Well,doing {bear} is probably better.") 20 print("Bear runs away.") 21 22 elif door == "2": 23 print("You stare into the endless abyss at Cthulhu's retina.") 24 print("1.Blueberries.") 25 print("2.Yellow jacket clothespins.") 26 print("3.Understanding revolvers yelling melodies.") 27 28 insanity = input(">") 29 30 if insanity == "1" or insanity == "2": 31 print("Your body survives powered by a mind of jello.") 32 print("Good job!") 33 else: 34 print("The insanity rots your eyes into a pool of muck.") 35 print("Good job!") 36 37 else: 38 print("You stumble around and fall on a knife and die.Good job!")
2 执行结果
PS E:\3_work\4_python\2_code_python\02_LearnPythonTheHardWay> python ex31.py You enter a dark room with two doors. Do you go through door #1 or door #2? >2 You stare into the endless abyss at Cthulhu's retina. 1.Blueberries. 2.Yellow jacket clothespins. 3.Underftanding revolvers yelling melodies. >4 The insanity rots your eyes into a pool of muck. Good job!
