Match Adventure

Backgroud

When it comes to programming, one of the classic examples is a text-based adventure game where you type in commands and explore your environment. In a text adventure, you type in commands such as "Go west" and "Pick up an apple", and get responses back based on the command chosen.

We are going to explore using the magic of Structural Pattern Matching, as introduced in PEP 636.

Understanding

Your player will need to have an inventory, stored as a dict containing the items as keys and the quantity as values. Your player will move in one of the four cardinal directions (north/south/east/west), and can pick things up if they are standing in front of them.

Your starting values:

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INVENTORY = {
    "apples": 0,
    "herbs": 0,
    "water": 0,
    "firewood": 0,
}

direction = "north"

Your program should accept the following commands, and have the following outputs. Words in curly braces {} can be any value in the list separated by a /.

Go {north/south/east/west/home}

The response for each choice should be:

north: You walk north and arrive at an orchard of apple trees.

south: You walk south and arrive at a field of healings herbs.

east: You walk east and arrive at a spring full of drinking water.

west: You walk west and arrive at a lumber yard full of firewood.

Valid directions should change the direction variable to the matched value.

home: You go home, ending your adventure here. Goodbye!

Going home should print end the game and exit the program.

If the word after Go is not a valid option, the response is You cannot go {choice 1}. Valid directions are north, south, east, west, and home.

Check compass

Response: You are facing {current direction}.

The default value, per the template, should be north.

Take {an/some} {apple/apples/herbs/water/firewood}

Response: You take {choice 1} {choice 2} and add to your inventory.

1 of the chosen item should be added to the inventory.

Count {item}

Response: You have {item count} {item} in your inventory.

Note that the proper name for the apples item (in the dict) should be apples while the Take command should accept either apples or apple.

Before You Begin

Execute cd by itself in your terminal window. You should find that your terminal window’s prompt resembles the below:

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$

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mkdir adventure

Then execute

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cd adventure

You should now see your terminal prompt as adventure/ . You can now execute

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code adventure.py

Specification

Your program should run outside of a function at the global level, making use of loops and match-case instead of functions to achieve the desired behavior.

Your program should begin with the following values:

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INVENTORY = {
    "apples": 0,
    "herbs": 0,
    "water": 0,
    "firewood": 0,
}

direction = "north"

Your program should start by printing the following line and then a prompt for input. Each prompt in the program should be at the beginning of its own line with a right angle bracket followed by a space: >

Your adventure has begun. You see an empty field in all directions. Your inventory is empty. Choose "Go home" to end your adventure.
> 

Your program should follow the response pattern described in the Understanding section of the problem.

Example Sequence:

Your program should produce results as follows:

Your adventure has begun. You see an empty field in all directions. Your inventory is empty. Choose "Go home" to end your adventure.
> Go north

You go north and arrive at an orchard of apple trees.
> Take an apple

You take an apple and add to your inventory.
> Go south

You walk south and arrive at a field of healings herbs.
> Take some herbs

You take some herbs and add to your inventory.
> Count herbs

You have 1 herbs in your inventory.
> Check compass

You are facing south.
> 

After the above sequence, your inventory and direction values should now be:

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INVENTORY = {
    "apples": 1,
    "herbs": 1,
    "water": 0,
    "firewood": 0,
}

direction = "south"

If the command the user gives is not a valid a case covered by the Understanding, the program should print:

Invalid directions, please try again.

Your program should continue until the user enters a command to Go home.

The catch: Your program should be able to handle all of these cases without using a single if statement! Only match-case statements.

How to Test

Run your program with python adventure.py and enter Go north, Take an apple, Go south, Take some herbs, Count herbs, and Go home. You should see the following sequence and end up back on the command line.

Your adventure has begun. You see an empty field in all directions. Your inventory is empty. Choose "Go home" to end your adventure.
> Go north

You go north and arrive at an orchard of apple trees.
> Take an apple

You take an apple and add to your inventory.
> Go south

You walk south and arrive at a field of healings herbs.
> Take some herbs

You take some herbs and add to your inventory.
> Count herbs

You have 1 herbs in your inventory.

> Drop herbs

Invalid directions, please try again.
> Go home

You go home, ending your adventure here. Goodbye!

If you run into an error saying your file cannot be opened, retrace your steps to be sure that you are inside your adventure folder and have saved your adventure.py file there.

You can execute the below to check your code using check50, a program that CS50 will use to test your code:

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check50 alum-challenges/problems/main/python/week-2/adventure/tests

Visit the URL that check50 outputs to see the input check50 handed to your program, what output it expected, and what output your program actually gave.

How to Submit

Coming soon