For Loop Help

[tjmck2]

Lets just assume the code below can't be altered. Can someone please explain to me the (last_index, -1, -1): part? I understand for i in range (last_index but I am unsure about the additional -1 -1). Thank you in advance

text = input('Line: ')
last_index = len(text) - 1
backwards_text = ''
for i in range(last_index, -1, -1):
  backwards_text = backwards_text + text[i]
print(backwards_text)

[striver]

First parameter in a range is the start of an iteration, second is the end and third is a step, so in your example:
* beginning is a length of text-1
* end is on 0 (step before -1)
* step is -1

e.g.

In [1]: for i in range(20, -1, -1):
   ...:     print i
   ...:     
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0

[snippsat]

Lets just assume the code below can't be altered. Can someone please explain to me the (last_index, -1, -1): part?

Should not use it,there is reversed() which most understand without explaining.

text = input('Line: ')
backwards_text = ''
for i in reversed(text):
    backwards_text += i

print(backwards_text)

There is also [::-1].

>>> s = 'hello'
>>> s[::-1]
'olleh'

[tjmck2]

Thanks everyone!