On Sun, Jan 5, 2014 at 12:24 PM, Göktuğ Kayaalp <s...@gkayaalp.com> wrote:
> Hi,
>
> AFAIK, we do not have "postfix conditionals" in Python, i.e. a condition
> appended to a
> statement, which determines whether the statement runs or not:
>
> py> for i in [False]:
> ... break if not i
>
> The above piece of code is equivalent to this in Python:
>
> py> for i in [False]:
> ... if not i
> ... break
>
> I believe that the first example is superior to the second example when the
> two is compared
> for readability and intuitiveness.
I'm going to have to disagree. I dislike how this obscures the
if-statement, complicates the language grammar, and adds another
unnecessary way to express the same thing (which violates TOOWTDI)
with little countervailing benefit.
> We already have a ternary statement that
> looks similar,
>
> py> print('hi') if True else None
Actually, to be pedantic, it's a ternary *expression*. Using it purely
for side-effects (i.e. as a statement) is rather unidiomatic, in the
same way that abusing list comprehensions, e.g.:
[print(i) for i in range(42)]
is frowned upon.
Not to mention that the ternary doesn't work for actual statements
(print() is just a function call in Python 3):
>>> (x = 1) if True else (x = 2)
File "<stdin>", line 1
(x = 1) if True else (x = 2)
^
SyntaxError: invalid syntax
> so I reckon there would be no breakage in old code if this kind of syntax
> was added. Ruby has
> this, and AFAIK Perl also does.
>
> I lack the knowledge of whether the community has opinions on this kind of
> notation, so I am
> posting this here instead of the ideas list. What are your thoughts on
> this?
You can already write:
for i in [False]:
if not i: break
if you feel the need for terseness or a one-liner. Perhaps this
satisfies your desire?
Cheers,
Chris
--
https://mail.python.org/mailman/listinfo/python-list
