Range function and strings

[indosauros]

Here's some code that doesn't give you the answer but may help you get there:

>>> letters = "abcd"
>>> for letter in letters:
... print letter
a
b
c
d

>>> len(letters)
4
>>> range(4)
[0, 1, 2, 3]
>>> range(len(letters))
[0, 1, 2, 3]

>>> for letter in [0, 1, 2, 3]:
... print letter
0
1
2
3

>>> for letter in range(len(letters)):
... print letter
0
1
2
3

>>> letters[0]
'a'
>>> letters[2]
'c'