On 7/10/07, Jacob Lee <[EMAIL PROTECTED]> wrote:
Closures have existed in Python since version 2.1 or so:
def f():
x = 5
return lambda: x
closure = f()
print closure() # prints 5
Here, the anonymous inner function returned by f is able to refer to
variables defined in outer scopes.
Oh, nice! This is did not know. So then are closures available now in IP?
As for the Python 3000 question --
The one current limitation is that you cannot rebind names defined in
outer scopes.
To me that's a feature, not a limitation. ;-)
That is, the following code does not work as expected:
def f():
x = 5
def g():
x = 7 # x is local to g here
You could use the "global" statement to indicate that x is a global
despite it being assigned to inside the function, but there was no
equivalent way to indicate that x refers to a variable in an outer, but
non-global, scope. Python 3000 will introduce the "nonlocal" statement that
works like the global statement to fill this gap. As usual, the best source
is the relevant PEP: http://www.python.org/dev/peps/pep-3104/
Hope this helps.
It does. Thanks!
--
/M:D
M. David Peterson
http://mdavid.name | http://www.oreillynet.com/pub/au/2354 |
http://dev.aol.com/blog/3155
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