[Tutor] Program for outputing the letter backward

[Hoffmann]

--- John Fouhy <john at fouhy.net> wrote:

> On 29/03/06, Hoffmann <oasf2004 at yahoo.com> wrote:
> > vehicle='car'
> > index = vehicle[-1]       #the last letter
> > index_zero = vehicle[0]   #the first letter
> >
> > while index >= index_zero:
> >    letter=vehicle[index]
> >    print letter
> >    index -= 1
> >
> > The problem is that I get no output here. Could I
> hear
> > from you?
> 
> I can print the letters backwards like this:
> 
> vehicle = 'car'
> print vehicle[2]
> print vehicle[1]
> print vehicle[0]
> 
> Output:
> 
> r
> a
> c
> 
> -----
> 
> This is not very useful, though, because it will
> only work for strings
> that are exactly three letters long.  Can you see
> how to write a loop
> to produe this output?
> 
> Hint: the len() function will tell you how long a
> string is.
> 
> eg: if vehicle == 'car' then len(vehicle) == 3.
> 
> --
> John.
> _______________________________________________

Hi John,

I am still 'blind' here.

Please, see below what I did, and what I got:

>>> vehicle='car'
>>> index = 0
>>> lenght =len(vehicle)
>>> last = vehicle[lenght -1]
>>> while last >= vehicle[0]:
...     letter = vehicle[index]
...     print letter
...     last -= 1
...
c
Traceback (most recent call last):
  File "<stdin>", line 4, in ?
TypeError: unsupported operand type(s) for -=: 'str'
and 'int'

As you can see, I am still a newbie...
Could anyone, please, guide me on this exercise?
Thanks!
Hoffmann

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