Below is my code for the Treasure Hunt Turtle exercise.

In this exercise, I applied a number of our previous lessons.

I used try/except statements to handle user input that was non-numerical. I had more trouble handling if the user inputted a number outside the range of -100 to 100 for the x or y-coordinates. I tried to give a “Bad input” error if the user, with the following code:

if user_x >= -100 and user_x <= 100:
      if user_y >= -100 and user_y <= 100:
        tina.penup()
        tina.goto(user_x, user_y)
        tina.stamp()'
...
else:
   print "Bad input"

I suspect it may be an issue of indentation. As this is the most complicated exercise we have written so far, there are many levels of indentation, and I am learning to keep track of that.

Other skills that I applied were the if/elif/else sequence, and asking for user input using input(). I used many of the built-in functions of the turtle module: penup() so that Tina did not draw lines all over the screen as the user guessed the treasure’s coordinates; goto(x,y) so that Tina would go to the coordinates the user inputted; stamp() so that the user could view their previous attempts on the screen. The code also uses the random module to hide the treasure at new, random coordinates every time the program is run:

treasure_x = random.randint(-100,100)
treasure_y = random.randint(-100,100)

by choosing a random x and random y in the range of -100 to 100. Speaking about modules, I learned about and used many functions from the math module. It’s very powerful! My favorite part of this exercise was when I wrote a formula for the distance between the user’s x and y coordinates and the treasure’s coordinates:

#distance formula between userx,y and treasurex,y
  distance= math.sqrt(math.pow((treasure_x - user_x),2) + math.pow((treasure_y - user_y),2))

My distance formula used the power function pow(x,p) which takes two arguments: what should be raised (x) and to what power (p). I also used the sqrt(x) function, which takes the square root of x. I had to pay attention to matching parenthesis in this calculation. Originally, I had thought to make distance a function, but when I realized the arguments were already defined in the code (the random treasur coordinates, the user input coordinates) I realized I could just define distance as a variable. I then based an if/elif/else sequence of statements based on the value of that distance variable.

if distance<= 5:
   still_going= False
   user_has_won= True
elif 5 < distance < 20:
   print("You're close! "+ str(distance) + " pixels away. Try again")
elif 20 < distance < 50:
   print("You're getting warmer! "+ str(distance) + " pixels away. Try again")
else:
   print( str(distance)+ " pixels away. Try again")

I used the variable and the if/elif/else sequence to give the user feedback on how close their guess was to the treasure’s coordinates. The feedback was definitely the most difficult part of the exercise, but once I thought of the distance variable it was pretty simple combined with elif statements.

What was new in this exercise also was executing most of my code in a while clause, within that while clause having both try/except statements and if/elif/else statements. I took a while for me to understand ‘while’ statements, but now I understand that the ‘while’ clause is only executed, and looped through, while the statement is True. Once the statement is false, the loop ends. If the user guessed the coordinates within 5 pixels, the following code would execute:

if distance<= 5:
   still_going= False
   user_has_won= True

If the user guessed correctly, I had to set still_going to False, so that the while loop would end. I also needed to change user_has_won to True. I then created another while loop that executed only if user_has_won was equal to True:

while user_has_won:
  congratulate(tina)

Therefore the congratulate function would only play if the user had guessed within 5 pixels of the coordinates. I may not have needed this extra while loop, but it made sense to me.

This exercise was a bit more challenging than the previous ones, but I appreciated the direction and it was exciting when I had a breakthrough and solved it! I look forward to the next challenge.