Can't compare tuples in 'if statement'

Posted by Foxington_the_First@reddit | learnprogramming | View on Reddit | 4 comments

Hi all,

I am writing a simple game in Python using the turtle library.

I want things to happen when a turtle I set to move randomly comes into contact with the turtle the player can manually control.

I was hoping to compare positions and say things like:

"if difference between x values is less than [amount] and difference between y values is less than [amount]:

then thing will happen."

The problem is turtle.pos() spits out a tuple (0.0, 0.0), so I can't directly compare them to find the difference. When I write this line of code:

difference = dragon.pos() - enemy.pos()

Error

TypeError: unsupported operand type(s) for Sub: 'tuple' and 'tuple' on line 44 in main.py

What is the best way to unpack the tuple so it can be compared? I tried using square bracket indexing to little avail.

Thanks!

[-]

hennipasta@reddit

dx, dy = dragon.pos()
ex, ey = enemy.pos()

aqua_regis@reddit

You could just as well unpack the tuples. Consider the following:

notes = ("A", "F")  # a tuple
(succeed, fail) = notes # here, the tuple gets unpacked in the two variables on the left

Think about how you could use that in your code.

teraflop@reddit

I tried using square bracket indexing to little avail.

Square bracket indexing is exactly what you need.

You said what you want to do is:

if difference between x values is less than [amount]and difference between y values is less than [amount]:

The x values are dragon.pos()[0] and enemy.pos()[0], so you can just subtract them to find the difference. And likewise for the y values which are at index 1.

Foxington_the_First@reddit (OP)

Oh great! I see the issue, I was putting the square brackets as an argument in the method for some reason. I will try with this syntax. Much appreciated!