[Python-ideas] Silent bugs - was Re: PEP8 operator must come before line break

[Chris Angelico]

On Fri, Apr 15, 2016 at 5:41 AM, Erik <python at lucidity.plus.com> wrote:
> On 14/04/16 20:22, Serhiy Storchaka wrote:
>>
>> An argument for operators "+" and "-":
>>
>>      result = expr1 +
>>      expr2
>>
>> is syntax error, while
>>
>>      result = expr1
>>      + expr2
>>
>> is silent bug.
>
>
> Interesting. But that bug potentially exists regardless of what PEP8 says.
>

Yes, but if you encourage people to spell it the first way, you can't
accidentally leave part of your expression out of your result.

However, I wouldn't write it like *either* of those. To me, the options are:

result = expr1 +
    expr2

and

result = expr1
    + expr 2

And either of those would give an immediate IndentationError without
the parentheses. So indenting the continuation is even better than
choosing where to place the binary operator.

ChrisA