Complex modification rules for Karabiner Elements to map shift keys to parentheses. Use the URL in the comment to import easily.

shift_to_parentheses.json

{
    "title": "Shift keys to parentheses",
    "rules": [
        {
            "description": "map left shift to opening parenthesis",
            "manipulators": [
                {
                    "type": "basic",
                    "from": {
                        "key_code": "left_shift",
                        "modifiers": {
                            "optional": [
                                "any"
                            ]
                        }
                    },
                    "to_if_alone": [
                        {
                            "key_code": "9",
                            "modifiers": [
                                "left_shift"
                            ]
                        }
                    ],
                    "to": [
                        {
                            "key_code": "left_shift",
                            "modifiers": []
                        }
                    ]
                }
            ]
        },
        {
            "description": "map right shift to closing parenthesis",
            "manipulators": [
                {
                    "type": "basic",
                    "from": {
                        "key_code": "right_shift",
                        "modifiers": {
                            "optional": [
                                "any"
                            ]
                        }
                    },
                    "to_if_alone": [
                        {
                            "key_code": "0",
                            "modifiers": [
                                "right_shift"
                            ]
                        }
                    ],
                    "to": [
                        {
                            "key_code": "right_shift",
                            "modifiers": []
                        }
                    ]
                }
            ]
        }
    ]
}

karabiner://karabiner/assets/complex_modifications/import?url=https%3A%2F%2Fgist.githubusercontent.com%2Feyemyth%2Fdb4f923bcbd640b2d71a5f3fa0670e3a%2Fraw%2Fe62566f8db8985c07eb33df9459f247561218614%2Fshift_to_parentheses.json