Dick Moores wrote:
Hi Dick,
>>> lst = [5,3,7,6,2] >>> lst.sort() >>> lst [2, 3, 5, 6, 7] >>> lst = [5,3,7,6,2] >>> print lst.sort() None >>> lst [2, 3, 5, 6, 7]I'm wondering why "print lst.sort()" doesn't print the newly sorted list, but instead prints "None". In fact, the sorting has taken place because of "print lst.sort()". Is this behavior a Good Thing in Python? Dick _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
A Python list sort is destructive, as you can see - it has modified lst. So, to emphasise that it is destructive, it returns None. You'll find this in most destructive methods and functions in Python.
OK, but returning the new list would seem to make more sense. Is the reason sort() doesn't, really only that it is better to emphasize that it is destructive?
However, as of Python 2.4, there's a new built-in function that has the functionality you want:
>>> x = [3,1,2]
>>> y = sorted(x)
>>> print y
[1, 2, 3]
>>> print x
[3, 1, 2]
You'll note that sorted() is not destructive - that is, x is not modified.
Didn't know about sorted(). Thanks, Liam.
Dick
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