not subscriptable error when not trying to subscript : We begin with a user inputted string containing only lower-case letters
```
for letter in encoded_input:
		if letter == ' ':
			decoded_output.append(' ')
			continue
		
		decoded_output.append(map_input(letter,tpos1,tpos2,tpos3))
```
and then pass to this function
```
def map_input(value,r1,r2,r3,wr=wiring,rf=reflector):#Use reflector as well
	pass1 = rf[r3[r2[r1[wr[ALPH.index(value)]]]]]
	r1,r2,r3 = reverse_rotors(r1,r2,r3)
	return ALPH[wr[r1[r2[r3[pass1]]]]]
```
where all of the variables passed are lists containing numbers 0-25 in a unique arrangement. 


#Problem
When I do this, however, I get an error telling me 

```
pass1 = rf[r3[r2[r1[wr[ALPH.index(value)]]]]]
TypeError: 'int' object is not subscriptable
```

Am I missing the obvious or is something subtle going on? Value is indeed a lower case letter in ALPH (which is just a list containing the alphabet).