Thanks. In case anyone else is looking, the recipe is at:
http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/303440
(which also shows how to make it work with python2.3 and below since
they don't support decorators)
Brian
--
http://mail.python.org/mailman/listinfo/python-list
Can anyone explain the behaviour of python when running this script?
>>> def method(n, bits=[]):
... bits.append(n)
... print bits
...
>>> method(1)
[1]
>>> method(2)
[1, 2]
It's the same in python 1.5, 2.3 and 2.4 so it's not a bug. But I
expected the variable "bits" to be re-initialised
Thanks, this makes perfect sense. The phrase which sums it up neatly is
"Default parameter values are evaluated when the function definition is
executed"
However, is there a good reason why default parameters aren't evaluated
as the function is called? (apart from efficiency and backwards
compatib
def function(arg=otherfunction(value)):
return arg
My expectation would have been that otherfunction(value) would be
called if (and only if) the arg keyword parameter was missing from the
function() call (ie. the optional value is evaluated the lazy way).
Also, otherfunction would be called each a
> Channelling the effbot, I think he was asking what namespace context
you
> expected the expression "arg=otherfunction(x)" to be evaluated in
when
> it's used at the time of a function call to dynamically create a new
> default value for arg.
Thanks, I realise now that's what was meant. I think I
