Reverse - how does it work?


#1



So, this code works with the assignment (I got it from reviewing a number of other posts on the assignment), but I have no idea how it works. Could someone please help with this? I remember reading somewhere that a negative index value starts on the right side of a list instead of the left, but I don't know why or how to continue that right-to-left iteration.


def reverse(text):
    newtext = ""
    for i in range(len(text)-1, -1, -1):
        newtext += text[i]
    return newtext


#2
range( start, stop, stride )

len(text) - 1 is the last character in the string, that's the starting point.

-1 is end of the range. We wish to stop on index[0], so the stop is set to one space to the left of that.

-1 is the stride, and being negative means from right to left.

Eg.

s u r p r i s e
len('surprise') == 8

so

range(7, -1, -1)

and the list that is created looks like this:

[7, 6, 5, 4, 3, 2, 1, 0]

#3

Thanks a bunch @mtf!


#4

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