Why has difference in the index of two codes

Question

s = "Hello"
for i in s:
print(s.index(i))
#___
print(s[0])
print(s[1])
print(s[2])
print(s[3])
print(s[4])

Answer 1

>>> help("str.index")
str.index = index(...)
S.index(sub[, start[, end]]) -> int

Like S.find() but raise ValueError when the substring is not found.

So...it finds a substring.

>>> for i in s:
... print(s.index(i))
...
0 # find 'H'
1 # find 'e'
2 # first 'l'
2 # There's no difference between 'l' and 'l'
4 # 'o'
>>>

To find the second 'l' you have to distinguish between them, set the start parameter, use a command that allows for occurrence, etc.

Answer 2

By the way:

Use enumerate() to extract indexes along with values.

http://stackoverflow.com/questions/522563/accessing-the-index-in-JUMP_LINK__&&__python__&&__JUMP_LINK-for-loops

Answer 3

If you were to change >s< to "Hello1" the first one would print "Hello1" the lower one would just print "Hello".
It might even crash if >s< is shorter than 5 chars