This is weird!!! It should work but I get an but I get a "ValueError: I/O operation"

[BashBedlam]

I don't see why you would want to quit () after printing True or False only once. Try it like this as see if it does what you're expecting.

def has_33(nums):
	length = len (nums) - 1
	for i in range (length):
		if nums [i] == 3 and nums [i+1] == 3:
			return True
	return False

print (has_33([1, 3, 1, 3]))
print (has_33([3, 1, 3]))
print (has_33([1, 3, 3]))