Lab 6: Text Adventure¶
Description of the Adventure Game¶
One of the first games I ever played was a text adventure called Colossal Cave Adventure. You can play the game on-line here to get an idea what text adventure games are like. Seriously, give it a try. Otherwise it will be hard to understand what we are trying to do here.
Arguably the most famous of this genre of game is the Zork series.
The first "large" program I created myself was a text adventure. It is easy to start an adventure like this. It is also a great way to practice using lists. Our game for this lab will involve a list of rooms that can be navigated by going north, east, south, or west. Each room will be a list with the room description, and then what rooms are in each of the directions. See the section below for a sample run:
You are in a dusty castle room. Passages lead to the north and south. What direction? n You are in the armory. There is a room off to the south. What direction? s You are in a dusty castle room. Passages lead to the north and south. What direction? s You are in a torch-lit hallway. There are rooms to the east and west. What direction? e You are in a bedroom. A window overlooks the castle courtyard. A hallway is to the west. What direction? w You are in a torch-lit hallway. There are rooms to the east and west. What direction? w You are in the kitchen. It looks like a roast is being made for supper. A hallway is to the east. What direction? w Can't go that way. You are in the kitchen. It looks like a roast is being made for supper. A hallway is to the east. What direction?
This game assumes you know the material up through Introduction to Lists.
Creating Your Dungeon¶
Before you start, sketch out the dungeon that you want to create. It might look something like this:
Next, number all of the rooms starting at zero.
Use this sketch to figure out how all the rooms connect. For example, room 0 connects to room 3 to the north, room 1 to the east, and no room to the south and west.
As a reminder, at the end of the year I do scan for duplicate homework. I keep all homework assignments from prior semesters, and assignments from non-Simpson students that I find on-line. I run a program that scans for duplicates. Make sure your work is your own.
mainfunction and call the
mainfunction, create an empty array called
room_list. If you've forgotten, see Create an Empty List.
Create a variable called
room. Set it equal to an array with five elements. For the first element, create a string with a description of your first room. The last four elements will be the number of the next room if the user goes north, east, south, or west. Look at your sketch to see what numbers to use. Use
Noneif no room hooks up in that direction. (Do not put
Nonein quotes. Also, remember that Python is case sensitive so
nonewon't work either. The keyword
Noneis a special value that represents "nothing." Because sometimes you need a value, other than zero, that represents )
Append this room to the room list. See Adding to a List if you've forgotten how to do that.
Repeat the prior two steps for each room you want to create. Just re-use the room variable.
Create a variable called
current_room. Set it to zero.
room_listvariable. Run the program. You should see a really long list of every room in your adventure. If you don't, make sure you are calling your
mainfunction at the end of your program, and that it isn't indented.
Adjust your print statement to only print the first room (element zero) in the list. Note that at index 0 is the description, 1 is the room to the north, 2 is the room to the east, etc. Run the program and confirm you get output similar to:
['You are in a room. There is a passage to the north.', 1, None, None, None]
room_list, print the current room the user is in. Since your first room is zero, the output should be the same as before.
Change the print statement so that you only print the description of the room, and not the rooms that hook up to it. Remember if you are printing a list in a list the index goes after the first index. Don't do this:
You are in a room. There is a passage to the north.
Create a variable called
doneand set it to
False. Then put the printing of the room description in a
whileloop that repeats until
doneis set to
True. We won't set
Before printing the description, add a code to print a blank line. This will make it visually separate each turn when playing the game.
After printing the room description, add a line of code that asks the user what they want to do. Use the
inputstatement. Keep in mind that you will be entering letters, therefore you will not want to convert what the user enters to an integer or floating point number. This will be similar to how we got input in Lab 4: Camel. The most frequent mistake I've seen students make is to have an
inputstatement and not capture the return value. See Capturing Returned Values if you have this issue.
ifstatement to see if the user wants to go north. You should accept user input like "n" and "N" and "North" and "NoRtH". You may need to review Text Comparisons and Multiple Text Possibilities.
If the user wants to go north, create a variable called
next_roomand get it equal to
room_list[current_room], which should be the number for what room is to the north. (Remember, 0 is the description, 1 is north, 2 is east, etc.)
ifstatement to see if the next room is equal to
None. If it is, print "You can't go that way." Otherwise (how do you do 'otherwise'?) set
next_room. Note: This new
ifstatement is part of the
ifstatement to go north. So make sure it is indented inside that
Test your program. Can you go north to a new room?
elifstatements to handle east, south, and west. Add an
elsestatement to let the user know the program doesn't understand what she typed.
It is a great idea to put blank lines between the code that handles each direction. I don't mean to print a blank line, but actually have blank lines in the code. That way you visually group the code into sections.
It is a great idea to add comments too, to each section.
Test your program. Make sure you have enough of a description that someone running the program will know what direction to go. Don't say "You are in the kitchen." Instead say "You are in the kitchen. There is a door to the north."
Add a quit command that ends the game.
Make sure that the program works for upper and lower case commands.
Have the program work if the user types in "north" or "n". Review Multiple Text Possibilities if needed.
Spend a little time to make this game interesting. Don't simply create an "East room" and a "West room." That's boring.
Also spend a little time to double check spelling and grammar. Without a word processor checking your writing, it is important to be careful. Pay particular note to:
Students often capitalize words in this lab that should not be capitalized. In particular, see when do you capitalize directions.
Do not capitalize room names unless the room name is part of a title. Don't say "You are in the Living Room," because the word "living room" isn't normally capitalized.
\n to add carriage returns in your descriptions so they don't print all on
one line. Don't put spaces around the
\n, or the spaces will print.
What I like about this program is how easy it is to expand into a full game. Using all eight cardinal directions (including "NorthWest"), along with "up" and "down" is rather easy. Managing an inventory of objects that can exist in rooms, be picked up, and dropped is also a matter of keeping lists.
Expanding this program into a full game is one of the two options for the final lab in this course.