On 7/11/2010 1:48 PM, wheres pythonmonks wrote:
2. How can I write a function, "def swap(x,y):..." so that "x = 3; y
= 7; swap(x,y);" given x=7,y=3??
(I want to use Perl's Ref "\" operator, or C's&).
(And if I cannot do this [other than creating an Int class], is this
behavior limited to strings,
tuples, and numbers)
Since you are just exploring, addendum to other answers:
>>> x,y = 1,2
>>> def swapxy():
global x,y
x,y=y,x
>>> swapxy()
>>> x,y
(2, 1)
Not too useful
>>> s = [1,2]
>>> def swap01(lis):
lis[:2] = reversed(lis[:2]) # other versions possible
>>> swap01(s)
>>> s
[2, 1]
A function can *modify* an input object. When is does, the usual
convention is that it should *not* return the object.
--
Terry Jan Reedy
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