Use the code given below:
>>> a = 'ZENOVW'
>>> b = sorted(a)
>>> print b
['E', 'N', 'O', 'V', 'W', 'Z']
And the sorted returns a list, so you can just make it a string again using join like this:
>>> c = ''.join(b)
Which will join the items of b together with an empty string '' in between each item.
>>> print c
'ENOVWZ'