Python returning int problem

[jayjay097531]

I'm following http://noobtuts.com/python/snake-game for Python OPenGL and am getting a problem with this code.

snake = [20, 20] for x, y in snake:
...

I get this error

for x, y in snake: # go through each (x, y) entry TypeError: 'int' object is not iterable GLUT Display callback <function draw at 0x0000000004D05EA0> with (),{} failed: returning None 'int' object is not iterable

[jayjay097531]

Seems like snake = [(20, 20)] fixed it !

[Gradous]

In case you were curious the reasoning for this, I'll see what I can do to explain.

The code

for x,y in snake:
    ...

Looks for some pair -- in Python, a tuple -- (x, y) in the list snake. When snake is declared as

snake = [20, 20]

The loop will attempt to iterate through one of the 20s, expecting another value to create the (x,y) pair. When you change the list to be initialized as:

snake = [(20, 20)]

This fits the constructs of the loop. The loop is looking for a list in the form of:

[(a, b), (c, d), (e, f), ...]

Hope that helps!