Unexpected formatting of subscript fluent interface

[petersaalbrink]

Black version: 22.1.0

Suppose I have a deeply nested dict-like object:

data = {
    "long_key_name_0": {
        "long_key_name_1": {
            "long_key_name_2": {
                "long_key_name_3": {
                    "long_key_name_4": {
                        "long_key_name_5": {
                            "long_key_name_6": {
                                "long_key_name_7": {
                                    "long_key_name_8": {"long_key_name_9": {}}
                                }
                            }
                        }
                    }
                }
            }
        }
    }
}

If I access a nested value using a chained getitem expression (cf. fluent interface), Black formats the subscript notation in the following way:

value = data["long_key_name_0"]["long_key_name_1"]["long_key_name_2"][
    "long_key_name_3"
]["long_key_name_4"]["long_key_name_5"]["long_key_name_6"]["long_key_name_7"][
    "long_key_name_8"
][
    "long_key_name_9"
]

However, this would be my desired format:

value = (
    data
    ["long_key_name_0"]
    ["long_key_name_1"]
    ["long_key_name_2"]
    ["long_key_name_3"]
    ["long_key_name_4"]
    ["long_key_name_5"]
    ["long_key_name_6"]
    ["long_key_name_7"]
    ["long_key_name_8"]
    ["long_key_name_9"]
)

This issue is related to the following open issues:

• Line too long: Attribute chain #510
• Strange formatting of fluent interface #571
• Unexpected line break in subscript #814
• Tiny slice gets pushed onto new lines #1280
• Use optional parentheses more often #2156
• how to comprehension black split []? #2566

However, since this issue is not exactly the same (as it is a combination between fluent interface and subscript notation), I decided to open a new issue for it.

Possible labels:

• linebreak
• design
• parentheses
• symmetry