On Mon, Mar 24, 2014 at 8:55 PM, Marko Rauhamaa <ma...@pacujo.net> wrote:
> Ian Kelly <ian.g.ke...@gmail.com>:
>
>> If lambda were going to be deprecated and removed then it already
>> would have happened in Python 3, because Guido tried to do precisely
>> that. I'm not sure what the reasons were for keeping it in the end
>> (according to PEP 3099 it was because nobody suggested a suitable
>> replacement), but if he couldn't get rid of it then, he never will.
>
> You never *need* (Python's) lambda for anything. Inner functions are
> more capable and almost always more readable. It doesn't hurt to have
> lambda, but I don't find any use for it, either.
They're often not more readable. A lot of people seem to equate
"verbose" with "readable", possibly by faulty extrapolation from
unreadably crunched code with one-letter variables and no line breaks.
But which of these is truly more readable?
squares = []
for n in range(30):
squares.append(n * n)
squares = [n * n for n in range(30)]
Similarly, there are plenty of cases where a nameless function is MUCH
clearer than breaking it out into a separate def and then using the
name once. Do you name the function for what it does internally?
def get_oneth_element_index(item):
return item[1].index
L.sort(key=get_oneth_element_index)
Or for how you're using it?
def keyfunc(item):
return item[1].index
L.sort(key=keyfunc)
Or do you just shortcut the whole thing by inlining it?
L.sort(key=lambda item:item[1].index)
Hey look, that's weakref.py line 941 right there. (It happens to be
the alphabetically last use of lambda in the stdlib. Made a good
example, although it'd be more common to have a space after that
colon.)
ChrisA
--
https://mail.python.org/mailman/listinfo/python-list
