I was trying to make the string HELLO to OHELL in Python. But couldn't get any way to rotate it without working with loops. How to code for it in just 1-2 lines so that I could get the desired pattern?
Here is one way:
def rotate(strg, n):
return strg[n:] + strg[:n]
rotate('HELLO', -1) # 'OHELL'
Alternatively, collections.deque ("double-ended queue") is optimised for queue-related operations. It has a dedicated rotate() method:
from collections import deque
items = deque('HELLO')
items.rotate(1)
''.join(items) # 'OHELL'
You can slice and add strings:
>>> s = 'HELLO'
>>> s[-1] + s[:-1]
'OHELL'
This gives you the last character:
>>> s[-1]
'O'
and this everything but the last:
>>> s[:-1]
'HELL'
Finally, add them with +.
Here is what I use to rotate strings in Python3:
To rotate left by n:
def leftShift(text,n):
return text[n:] + text[:n]
To rotate right by n:
def rightShift(text,n):
return text[-n:] + text[:-n]