object_reference_hints.md

Remember that multiple variables can refer to the same object.

In the diagram below, there are only 2 Room objects, total. (There are more in the game, obviously, but in this diagram, there are 2.)

There are 5 variables. 3 of them point to the one Room object that is the foyer:

• room['foyer']
• room['outside'].n_to
• player.location

The remaining 2 point to the one Room object that is the outside:

• room['outside']
• room['foyer'].s_to

room['outside'] -> Room("Outside Cave Entrance")
                               ^
                               |
                     room['foyer'].s_to


room['foyer'] -> Room("Foyer") <- player.location
                     ^
                     |
              room['outside'].n_to

If you want to move the player (who is in the foyer in the diagram) to another room, you just need to reassign that to any variable that points to that other room.

So if the player is in the foyer and types s to go south, we could set:

player.location = room['foyer'].s_to  # we were in the foyer, then went south

and after that, the variable references would look like this, with player location pointing to the outside object:

                        player.location
                               |
                               v
room['outside'] -> Room("Outside Cave Entrance")
                               ^
                               |
                     room['foyer'].s_to


room['foyer'] -> Room("Foyer")
                     ^
                     |
              room['outside'].n_to

Assigning doesn't copy the object. It just makes another reference to the same object.