On Fri, 28 Nov 2008 00:06:01 -0800, bearophileHUGS wrote:
>>For this to change wouldn't be a little change, it would be a large
>>change.<
>
> I see, then my proposal has little hope, I presume. I'll have to keep
> moving functions outside to test them and move them inside again when I
> want to run them.
Not so. You just need to prevent the nested functions from being garbage
collected.
def foo(x):
if not hasattr(foo, 'bar'):
def bar(y):
return x+y
def foobar(y):
return 3*y-y**2
foo.bar = bar
foo.foobar = foobar
return foo.bar(3)+foo.foobar(3)
However, note that there is a problem here: foo.bar will always use the
value of x as it were when it was called the first time, *not* the value
when you call it subsequently:
>>> foo(2)
5
>>> foo(3000)
5
Because foo.foobar doesn't use x, it's safe to use; but foo.bar is a
closure and will always use the value of x as it was first used. This
could be a source of puzzling bugs.
There are many ways of dealing with this. Here is one:
def foo(x):
def bar(y):
return x+y
def foobar(y):
return 3*y-y**2
foo.bar = bar
foo.foobar = foobar
return bar(3)+foobar(3)
I leave it as an exercise for the reader to determine how the behaviour
of this is different to the first version.
--
Steven
--
http://mail.python.org/mailman/listinfo/python-list
