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Python Python Collections (2016, retired 2019) Dungeon Game Hit points

Andrei Oprescu
Andrei Oprescu
9,547 Points

What have I done wrong in my code?

Hi!

I am currently doing a challenge which has a question like this:

Our game's player only has two attributes, x and y coordinates. Let's practice with a slightly different one, though. This one has x, y, and "hp", which stands for hit points. Our move function takes this three-part tuple player and a direction tuple that's two parts, the x to move and the y (like (-1, 0) would move to the left but not up or down). Finish the function so that if the player is being run into a wall, their hp is reduced by 5. Don't let them go past the wall. Consider the grid to be 0-9 in both directions. Don't worry about keeping their hp above 0 either.

The code that I am using is at the bottom of the question.

Why Is my code wrong and how could I improve?

Thanks!

Andrei

movement.py
# EXAMPLES:
# move((1, 1, 10), (-1, 0)) => (0, 1, 10)
# move((0, 1, 10), (-1, 0)) => (0, 1, 5)
# move((0, 9, 5), (0, 1)) => (0, 9, 0)

def move(player, direction):
    x, y, hp = player
    dx, dy = direction
    if x == 0:
        if dx == -1:
            hp -= 5
        else:
            x += dx
    elif x == 9:
        if dx == 1:
            hp -= 5
        else:
            x += dx
    elif y == 0:
        if dx == -1:
            hp -= 5
        else:
            y += dy
    elif y == 9:
        if dx == 1:
            hp -= 5
        else:
            y += dy
    return x, y, hp

2 Answers

Steven Parker
Steven Parker
220,526 Points

It looks like you have a good basic idea, but your implementation assumes that the motion will always be a single unit (plus or minus) in one or both directions.

The instructions don't say explicitly, and none of the examples show it, but perhaps the motions they test with include some that move farther than one unit.

Andrei Oprescu
Andrei Oprescu
9,547 Points

Hi again!

I have followed your instructions and I came up with this code:

def move(player, direction): x, y, hp = player dx, dy = direction if x + dx is False: hp -= 5 else: x += dx elif x + dx > 9: hp -= 5 else: x += dx elif y + dy is False: hp -= 5 else: y += dy elif y + dy > 9: hp -= 5 else: y += dy return x, y, hp

When I run this code I gives me:

Bummer! Try again!

Does this mean I have typed something incorrectly?

Thanks!

Andrei

Steven Parker
Steven Parker
220,526 Points

Use the instructions for code formatting in the Markdown Cheatsheet pop-up below the "Add an Answer" area. :arrow_heading_down:
Or watch this video on code formatting.

But even unformatted, I spot a few issues:

  • an "else" ends a conditional sequence, so "elif" can't follow it — but you can start a new "if"
  • the sum of two numbers cannot be "False" — did you mean to test for < 0?
  • don't change either coordinate until you know both are valid
Andrei Oprescu
Andrei Oprescu
9,547 Points

Thanks!

Your advice on how to fix my code worked.

I used a code like this:

def move(player, direction):
    x, y, hp = player
    dx, dy = direction
    if x + dx < 0:
        hp -= 5
    elif x + dx > 9:
        hp -= 5
    else:
        x += dx

    if y + dy < 0:
        hp -= 5 
    elif y + dy > 9:
        hp -= 5
    else:
        y += dy
    return x, y, hp

Thank you for also showing me how to format my code in a question.

Andrei