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

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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.

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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.

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

There is also [::-1].

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

[tjmck2]

Thanks everyone!