A small question about PEP 8

[Steven D'Aprano]

On Mon, 08 Jul 2013 11:39:21 +0100, Joshua Landau wrote:

> On 8 July 2013 00:32, Xue Fuqiao <xfq.free at gmail.com> wrote:
>> Hi all,
>>
>> (English is not my native language; please excuse typing errors.)
>>
>> I'm a Python newbie and just started reading PEP 8.  PEP says:
>>
>> -----------------------------------------------------------------------
>> |The closing brace/bracket/parenthesis on multi-line constructs may
>> |either line up under the last item of the list, as in: |
>> |my_list = [
>> |    1, 2, 3,
>> |    4, 5, 6,
>> |    ]
>> |result = some_function_that_takes_arguments(
>> |    'a', 'b', 'c',
>> |    'd', 'e', 'f',
>> |    )
>> -----------------------------------------------------------------------
>>
>> I think the last item in my_list/result is 6/'f', respectively.  So why
>> doesn't the bracket/paren line up _under_ the last item?  ISTM the code
>> isn't consistent with the description.
>>
>> I have searched the archive of c.l.p and the web, but nothing helped.
>> Can anyone point me in the right direction?
> 
> You will grow to be a wonderful pedant. What it means is that the
> indentation will match the last one.

That's obvious from the example given, but that's nothing like the 
description given.




 Imagine:
> 
> """
> a_wonderful_set_of_things = {
>     bannanas_made_of_apples,
>     chocolate_covered_horns,
>     doors_that_slide,
>     china_but_on_the_moon,
>     buffalo_with_windy_hair,
>     not_missing_an_end_brace
> """¹
> 
> Now, there are several places you can put the end brace. You can (be a
> massive fool and) put it after the last item:
> 
> """
> a_wonderful_set_of_things = {
>     ...,
>     not_missing_an_end_brace}
> """

Well, call me a fool then, because when I have code that extends over 
*one* additional line, I prefer that:

    raise ValueError(
            "Some error message too long to fit on the above line")

rather than:

    raise ValueError(
            "Some error message too long to fit on the above line"
            )


> You can also (be a fool and) put it at the same *indentation*:
> 
> """
> a_wonderful_set_of_things = {
>     ...,
>     not_missing_an_end_brace
>     }
> """

Call me a fool again, since I prefer this when there are more than one 
additional line. At least this time I'm in good company, since that's 
recommended by PEP 8.


> Or you can (be sane) and put it at no indentation:
> 
> """
> a_wonderful_set_of_things = {
>     ...,
>     not_missing_an_end_brace
> }
> """

I consider that the least aesthetically pleasing, and also rather awkward:


some_result = some_function(
        arg1, arg2, arg3, arg4, 
        [item1, item2, item3, item4,
              item5, item6, item7, 
              item8, item9, item10,
], 
       arg6, key=spam, word=eggs, 
       extras=None, foo=bar,
)


 
-- 
Steven