Line breaks should occur before the binary operator to keep all operators aligned.

This rule was changed on April 16th, 2016 in this commit. The tool is updated to recommend that line breaks should occur before the binary operator because it keeps all operators aligned. However older versions of tooling can still recommend the previous behaviour. See also W503.

Anti-pattern

income = (gross_wages +
          taxable_interest)

Best practice

income = (gross_wages
          + taxable_interest)