On 11/09/2015 09:42, Steven D'Aprano wrote:
On Fri, 11 Sep 2015 10:35 am, Ian Kelly wrote:
On Thu, Sep 10, 2015 at 4:25 PM, <t...@freenet.de> wrote:
[...]
So the compiler knows the distiction between global and local already.
As we've said before, it doesn't. The compiler's current rules are
fairly simple:
1) If it's in the function's argument list, it's an argument (and
therefore local).
2) If it's explicitly declared global, then it's global.
3) If it's never assigned within the function, then it's global.
Almost. If it's never assigned within the function, then it is looked up
according to the non-local scoping rules:
- closures and enclosing functions (if any);
- globals;
- builtins;
in that order.
4) Otherwise, it's local.
"Otherwise" meaning "if it is assigned to", except that "del" counts as an
assignment. That is:
def spam():
del x
makes x a local variable inside the function spam.
There's also a bunch of specialised and complicated rules for what happens
if you make a star import ("from module import *") inside a function, or
call eval or exec without specifying a namespace. Both of these things are
now illegal in Python 3.
And lastly, in Python 3 only, there is also a nonlocal declaration which
works like global except it applies only to closures and enclosing
functions.
Another proof about identation:
The parser can recognise identation with tabs and spaces.
You can use tabs *or* spaces.
In Python 3.
In Python 2, you can mix tabs *and* spaces, and Python will try to guess
what you mean. This causes more trouble than it is worth, and is removed in
Python 3.
[...]
I really doubt that you're going to gain any traction with this one,
because the decision that was made with Python 3 was to make the
compiler *more* rigid about not mixing tabs and spaces, not less.
Correct.
[...]
Who is responding or has responded?
Extreme Programmers, Python-Hardliner, Python-Evangelists, ... .
Presumably no core Python Programmers (wrting compiler and standard
library stuff)
Ad hominem.
For the record, I am the author of the statistics module in Python 3.4, and
Terry Reedy is the very active maintainer of IDLE. If I have missed anyone,
my apologies. So, yes, there are core developers here.
(Although not any of the senior core devs, as far as I know.)
IIRC Serhiy Storchaka pops in occasionally, as on the one genuine report
from the RUE about the FSR. Slight aside, I swear blind that Serhiy
never sleeps as he always seems to be doing something on the bug tracker.
--
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.
Mark Lawrence
--
https://mail.python.org/mailman/listinfo/python-list
