你已经学会了 if 语句、函数、还有列表。现在你要练习扭转一下思维了。把下面的代码写下来，看你是否能弄懂它实现的是什么功能。

from sys import exit

def gold_room():
    print "This room is full of gold.  How much do you take?"

    next = raw_input("> ")
    if "0" in next or "1" in next:
        how_much = int(next)
    else:
        dead("Man, learn to type a number.")

    if how_much < 50:
        print "Nice, you're not greedy, you win!"
        exit(0)
    else:
        dead("You greedy bastard!")


def bear_room():
    print "There is a bear here."
    print "The bear has a bunch of honey."
    print "The fat bear is in front of another door."
    print "How are you going to move the bear?"
    bear_moved = False

    while True:
        next = raw_input("> ")

        if next == "take honey":
            dead("The bear looks at you then slaps your face off.")
        elif next == "taunt bear" and not bear_moved:
            print "The bear has moved from the door. You can go through it now."
            bear_moved = True
        elif next == "taunt bear" and bear_moved:
            dead("The bear gets pissed off and chews your leg off.")
        elif next == "open door" and bear_moved:
            gold_room()
        else:
            print "I got no idea what that means."


def cthulhu_room():
    print "Here you see the great evil Cthulhu."
    print "He, it, whatever stares at you and you go insane."
    print "Do you flee for your life or eat your head?"

    next = raw_input("> ")

    if "flee" in next:
        start()
    elif "head" in next:
        dead("Well that was tasty!")
    else:
        cthulhu_room()


def dead(why):
    print why, "Good job!"
    exit(0)

def start():
    print "You are in a dark room."
    print "There is a door to your right and left."
    print "Which one do you take?"

    next = raw_input("> ")

    if next == "left":
        bear_room()
    elif next == "right":
        cthulhu_room()
    else:
        dead("You stumble around the room until you starve.")


start()

你应该看到的结果?
下面是我玩游戏的过程：

$ python ex35.py
You are in a dark room.
There is a door to your right and left.
Which one do you take?
> left
There is a bear here.
The bear has a bunch of honey.
The fat bear is in front of another door.
How are you going to move the bear?
> taunt bear
The bear has moved from the door. You can go through it now.
> open door
This room is full of gold.  How much do you take?
> asf
Man, learn to type a number. Good job!
$

加分习题:
1.把这个游戏的地图画出来，把自己的路线也画出来。
2.改正你所有的错误，包括拼写错误。
3.为你不懂的函数写注解。记得文档注解该怎么写吗？
4.为游戏添加更多元素。通过怎样的方式可以简化并且扩展游戏的功能呢？
5.这个 gold_room 游戏使用了奇怪的方式让你键入一个数字。这种方式会导致什么样的 bug？ 你可以用比检查 0、1 更好的方式判断输入是否是数字吗？int() 这个函数可以给你一些头绪。

    next = raw_input("> ")
    #if "0" in next or "1" in next:
    if str.isdigit(next) == True:
        how_much = int(next)

至此，笨方法学python-ex35-分支和函数这一小节的学习结束了。