Long dict key with operators are oddly broken into multiple lines

[yilei]

Describe the style change

Examples in the current Black style

tests = [
    (
        BusinessHour(),
        {
            Timestamp("2014-07-04 15:00")
            + Nano(5): this_is_a_very_long_function("2014-07-04 16:00"),
            Timestamp("2014-07-04 16:00")
            + Nano(5): this_is_a_very_long_function("2014-07-04 16:00"),
            Timestamp("2014-07-04 16:00")
            - Nano(5): this_is_a_very_long_function("2014-07-04 16:00"),
        },
    ),
]

Desired style

tests = [
    (
        BusinessHour(),
        {
            Timestamp("2014-07-04 15:00") + Nano(5): (
                this_is_a_very_long_function("2014-07-04 16:00")
            ),
            Timestamp("2014-07-04 16:00") + Nano(5): (
                this_is_a_very_long_function("2014-07-04 16:00"),
            ),
            Timestamp("2014-07-04 16:00") - Nano(5): (
                this_is_a_very_long_function("2014-07-04 16:00")
            ),
        },
    ),
]

Additional context

This is an example found in #3440 while working on the dict value. I think the issue is that we don't treat : as a delimiter thus the "operators" are broken instead of :.

[felix-hilden]

You got my vote 👍

[ichard26]

Go ahead! The current style is awful.