2018-05-23 17:54 GMT+03:00 Mike Miller <python-id...@mgmiller.net>:
>
> On 2018-05-22 14:32, Kirill Balunov wrote:
>
>> # in global scope everything works ok since locals is globals
>> >>> while len( this( val = dummy() ) ) >= 0:
>> ... print(val)
>> [0, 1]
>> [0, 1, 2]
>> [0, 1, 2, 3]
>>
>
> Interesting! Although the example with a len() and mutable default
> arguments obscured the utility, I thought. Also, why limit it to one
> assignment?
>
>
I just want some dummy example which can not be trivially handled with `for
name in iter(func, value)`. But the latter is also only partly true. You
can make something like:
class P:
__slots__ = ('func')
def __init__(self, func):
self.func = func
def __eq__(self, other):
return not self.func(other)
for val in iter(dummy, P(lambda x: len(x) < 5)):
print(val)
[0, 1]
[0, 1, 2]
[0, 1, 2, 3]
The only restriction is that you can not pass arguments to a `func`, but
this, to some extent, can also be handled with lambda. I limit it to _one
assignment_ firstly to make it simple, and secondly to get rid of some edge
cases.
> Liked Terry's suggestions for name. The name that jumped into my brain as
> I read was a reuse of the locals() or globals() callable with key words,
> that would change their behavior to what you suggest.
I like `this` because it is easy to follow in my opinion: " While this name
assigned to an expression is greater than zero do... " But of course I'm
open to any other spelling. I'm just wondering, if someone like this form
as an alternative for assignment expression (`:=`).
With kind regards,
-gdg
_______________________________________________
Python-ideas mailing list
Python-ideas@python.org
https://mail.python.org/mailman/listinfo/python-ideas
Code of Conduct: http://python.org/psf/codeofconduct/
