Pycodestyle: E125 overreaches pep8

[jeblair]

In pep8 version 1.3.3, E125 will erroneously alert on the following code:

if (foo == bar and
    bar == foo):
    qux = foo

citing:

E125 continuation line does not distinguish itself from next logical line

However, that sentence is a clause that only applies to hanging indentation, _not_ to vertically aligned lines joined inside parenthesis. Here is the relevant statement from pep8:

Continuation lines should align wrapped elements either vertically
using Python's implicit line joining inside parentheses, brackets
and braces, or using a hanging indent. When using a hanging indent
the following considerations should be applied; there should be no
arguments on the first line and further indentation should be used
to clearly distinguish itself as a continuation line.

Note that the additional considerations do not apply to anything but a hanging indent.

[slacy]

Agreed, and I'm going to have to globally disable E125 because of this. :(

[florentx]

The PEP8 sentence is about readability. Even if it does not forbid strictly this case, it has the same consequence on readability.

The above example might be rewritten like:

if (foo == bar and
        bar == foo):
    qux = foo

or (a preference for it)

if ((foo == bar and
     bar == foo)):
    qux = foo

or (but I don't like)

if (
    foo == bar and
    bar == foo
):
    qux = foo

[dev97]

It's unfortunate coincidence that "if<space>(" takes exactly 4 spaces. But indenting code like in first snippet is very very ugly. Second snippet resembles the way to hush gcc when assignment is intentional inside condition [if ((c = get_token())) ...], but in case with gcc it's for tricky code and acts as a warn sign. But to use it for every multiline condition that's too much. I don't have words about third snippet ;-)

Fortunately E125 can be globally disabled in ~/.config/pep8.

Nevertheless even the PEP8 reference code (see class Rectangle, if statement) explicitly shows that traditional indentation (when continuation indented relative to opening bracket) is valid.

[il86be]

I would suggest to indent the conditional block relative to the last line of the condition:

if (foo == bar and
    bar == foo):
        qux = foo

but pep8 1.3.3 still complains on such code. It seems that it does not even look at the "next logical line" when it reports E125

[florentx]

no this indentation will not be supported by pep8, because the recommended indentation is 4 spaces per level.

And I totally agree with this rule. If you use 8 spaces like the above example, it adds some confusion: do you indent to 4 or 8 in the elif or the else clause?
And if you change the conditional later, you'll have to re-indent the whole paragraph in this case.

By the way, since version 1.4.2 I've implemented the proposal of issue #151 to accept this form too:

if foo == bar and \
   bar == foo:
    qux = foo

It is an alternative to the other proposals (copied from a previous message):

if (foo == bar and
        bar == foo):
    qux = foo

if ((foo == bar and
     bar == foo)):
    qux = foo

[jeblair]

Hi,

Can we get back to the original topic of this bug? I did not suggest any alternate indentation. Merely that E125 is not supported by the text in the pep 8 specification that it claims to be. And dev97 helpfully pointed to an example in pep 8 that explicitly contradicts E125.

Following the specification is important because it's what editors and other tools are written to use. Especially since this tools is _named after_ the specification, it should follow it.

Please adjust the test for E125 to match the specification, thanks.

[florentx]

The proposed branch splits E125 error. It allows to skip E129 if it matches your preferences.

[john-aws]

Using elif in the same way does not cause E125, presumably because it's longer resulting in distinct indentation for the elif arm.

if (index1 == 5 and
    index2 == 3): # raises E125
    pass
elif (index1 == 6 and
      index2 == 1): # clean
    pass

[akaihola]

For future reference, the Stack Overflow question Python style: multiple-line conditions in IFs has a comprehensive set of style suggestions for long if conditions.

I know this ticket isn't about alternatives but strictly following the spec, but this link is worth mentioning since this page is among the top search results for "pep8 continuation line".

[florentx]

In next version of pep8 you can add E129 to the ignore list: 3f340b8b02d.