Avoid using global without confusing new programming students in Python?

Question

I\'ve been teaching 8th-9th graders basic computer programming for two weeks, and yesterday I tried to show them how they could make real simple text-adventure games in Pyth

Answer 1

I would encourage them to start learning OO

class Location:
     name="a place"
     description = "A dark place.  there are exits to the North and East"
     exits = "North","East"
     def __str__(self):
         return "%s\n%s"%(self.name,self.description)


class Player:
     current_location = "Home"
     inventory = ["Blue Key","Magic Thumbtacks"]
     health = 100
     name = "Unknown"
     def __init__(self,name):
         self.name = name

player = Player("Player 1")
loc = Location()
print loc
x = input("Input:")

To be honest a game is a difficult concept (even a text adventure). But I would start them directly on OO concepts, they will benefit more from that in the long term.

Granted this example is very small and leaves a lot of implementation details out.

An unrelated but better OO example would be:

class Animal:
     voice = '...'
     def speak(self):
         return "A %s Says '%s'"%(self.__class__.__name__, self.voice)

class Dog(Animal):
     voice = "Bark, Bark"

class Duck(Animal):
     voice = "Quack, Quack"

print Dog().speak()
print Duck().speak()

Answer 2

Assuming you want to keep things as simple as possible (no OO) and want to avoid introducing the global keyword, you could instead use a state dictionary and assign variables in there.

state['hasKey'] = True

Since access to this dict is not a variable assignment you avoid introducing the global keyword and at the same time can teach how to use a dict (checking for keys etc.)

Of course you still use a global variable and don't really address the issue of good coding style. But on the other hand, it could serve as an introduction to scopes and namespaces.