How to change element index of array?

Question

I have a variable string, example

a = 'swift'

and if I shift all characters to the left 1 time it becomes a = 'wifts' and if I shift to right 2 times it becomes a = 'tswif'

How to do this? I tried this function:

a = 'swift'
for x in range(len(a)-1):
    a[x+1]

and the result is 'wift'

I expect the output if I shift to left 1 times it becomes a = 'wifts' and if I shift to right 2 times it becomes a = 'tswif'

You certainly didn't try the 'function' you pasted here, as this would just give an error before doing nothing. Please paste your real code here. — Thierry Lathuille, Aug 22 '19 at 14:45
see https://stackoverflow.com/questions/48607319/rotating-strings-in-python — Dan, Aug 22 '19 at 14:49
@Nico The first problem is that a is not a string, the interpreter has no idea what `swift` is, it should be `"swift"`. Second is you're no reassigning anything. Other than that, you're not too far from an answer. — ofthegoats, Aug 22 '19 at 14:49
`a = swift` would cause a NameError, unless you have defined a `swift` variable before. Also, `a[x+1]` just does nothing, so there is no way you would get a result. So, please edit your question. — Thierry Lathuille, Aug 22 '19 at 14:50
@Nico There is no way the code in your question can produce what you say it does. Run it exactly as you pasted it and see how it doesn't output anything. So, as already requested, please provide us with a [mcve]. — Thierry Lathuille, Aug 22 '19 at 15:00

score 0 · Answer 1 · answered Aug 22 '19 at 14:55

0

You don't need a for loop, you can simply recreate the string concatenating the left and right part:

a = 'swift'
shift_amount = 2
a_shifted_left  = a[shift_amount:] + a[:shift_amount]
a_shifted_right = a[-shift_amount:] + a[:-shift_amount]

answered Aug 22 '19 at 14:55

Giampietro Seu

score 0 · Accepted Answer · edited Aug 22 '19 at 14:58

0

Expanded on the answer from here:

def shifting(string, number):
    return string[-number:] + string[:-number]

negative numbers are left shifts, and positive numbers are right shifts

edited Aug 22 '19 at 14:58

rinkert

answered Aug 22 '19 at 14:56

ofthegoats

2 Answers2