There is no built in "reverse" function in Python's str object. What is the best way of implementing this?
If supplying a very concise answer, please elaborate on it's efficiency. Is the str converted to a different object, etc.
+38
A:
How about:
>>> 'hello world'[::-1]
'dlrow olleh'
This is extended slice syntax. It works by doing [begin:end:step] - by leaving begin and end off and specifying a step of -1, it reverses a string.
Paolo Bergantino
2009-05-31 02:11:46
+9
A:
@Paolo's s[::-1] is fastest; a slower approach (maybe more readable, but that's debatable) approach is ''.join(reversed(s)).
Alex Martelli
2009-05-31 02:13:54
A *lot* faster:$ python -m timeit s='s = "abcdef"' 'mystr = mystr[::-1]'1000000 loops, best of 3: 0.263 usec per loop$ python -m timeit s='s = "abcdef"' 'mystr = "".join(reversed(mystr))'100000 loops, best of 3: 2.29 usec per loop
telliott99
2010-01-23 17:55:45