Python Forum

Ok I built a very basic caesar wheel...(w/out modules/classes). There was more trial/error than I care to admit . But, I came across something I couldn't figure out. Here is the relevant snippet.

base_wheel = ['a','b','c','d','e','f','g','h','i','j','k','l','m','n',
'o','p','q','r','s','t','u','v','w','x','y','z']

new_wheel1 = []
new_wheel2 = []

spinner1 = random.randint(0,25)
spinner2 = spinner1

for b in base_wheel:
	new_wheel1.append(base_wheel[spinner1])
	spinner1 -= 1#no problem with decrementing
for b in base_wheel:
	new_wheel2.append(base_wheel[spinner2])

	#why does += 1 (below) go over range?  I am looping elements of base_wheel
	#loop is finite so spinner2 must also terminate
	spinner2 +=1

very puzzling to me... thx in advance...

What is unclear? You have some initial value and you add 26 to it. It will always be greater than 25 (max index in wheel). You don't have problem with decreasing, because python also supports negative indexes. I.e. base_wheel[-1] is z

---

I.e any value between -25:25 is valid index

add a print statement on line 14:

print('spinner1: {}, spinner2: {}'.format(spinner1, spinner2))

and watch it. The error should become apparent

You may want to check modulo operator %