Readability of the code is not mere style, and can directly translate into errors being more visible. Compare:

    a_variable = (
       'lorum ipsum dolor sit amet ' +
       'my poor memory has left me quite upset ' +
       'for i cannot remember what word comes next '
       'in this long descriptive text' +
       'surely this is bound for the incinerator ' +
       'but remember any haiku can end, refrigerator.'
    )

But now if I choose to align certain characters:

    a_variable = (
       'lorum ipsum dolor sit amet'
       + ' my poor memory has left me quite upset'
       * ' for i cannot remember what word comes next'
       ' in this long descriptive text'
       + 'surely this is bound for the incinerator '
       + ' but remember any haiku can end, refrigerator.'
    )

… the errors in the first version are now plainly obvious. (Both the missed space, as well as the missed +.)

(This is an example. Yes, there are languages for which you don't need the +. There are some for which you do, however. There are also some that resist having the + moved about: for example, in Javascript, the parens become required, or you'll trigger the horrid auto-semicolon "feature".)

Hmm? You have not changed alignment, as all your lines of code start on the same integer indentation boundary. You just moved the operator to the beginning of the line, and changed the bug between the two examples.

Either you misunderstood what we mean by alignment (single whitespace separating operators and operands are not alignment), or maybe you tried to indent the first string literal further to align the string literal start boundaries. I sincerely hope it wasn't the latter...

Putting the operator on the second line, at the same indentation level, is a perfectly fine, indentation- and alignment-agnostic stylistic choice, and has its uses.

> You have not changed alignment

I have changed the alignment of both ' ' and '+' characters between the two examples, from not being aligned to being aligned.

> as all your lines of code start on the same integer indentation boundary

Indentation is not the only thing "style" guides enforce.

> and changed the bug between the two examples.

The bug should be the same in both examples, though I do see I transposed a '+' into an '*'. That wasn't intentional; the two are supposed to form the same AST, but with purposeful alignment in the second making bugs in both far more visible.

(You seem to be using "alignment of characters" to mean "alignment with indentation", which is more limiting than I would take "Aligning a character on one line with an arbitrary character on another line" to be.)

>purely a choice of style

Sure, but could i not say the same of using any indentation at all?

Would you consider a file without any indentation as readable and practical as a file without single-space alignments?

Not to mention that in languages like Python, indentation is syntax.