你需要通过键/值来重新定义，从list创建新值，然后用新值更新dict：

json_data = {
    "field A": 117,
    "field B": 143,
    "field C": 27,
    "field D": [
        {"id": 782, "name": "Some test A", "type": "Group"}
    ],
    "field E": None,
    "field F": "contact",
    "field G": [
        {"id": 32358, "name": "Some test B", "type": "Note"},
        {"id": 37557, "name": "Some test C", "type": "Note"},
        {"id": 38416, "name": "Some test D", "type": "Note"}
    ],
    "field H": None,
}

items=[]
for key, values in json_data.items():
    if isinstance(values, list):
      new_value = ' \n '.join([value['name'] for value in values])
      items.append((key, new_value))

json_data.update(items)

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输出量：

{'field A': 117,
 'field B': 143,
 'field C': 27,
 'field D': 'Some test A',
 'field E': None,
 'field F': 'contact',
 'field G': 'Some test B \n Some test C \n Some test D',
 'field H': None}

型

一个非常特定于结构的代码可以是：

new_dico = {}
for k, v in dico.items():
    if isinstance(v, list):
        # if the value in key value pair, is a list, 
        # it may contain dict with names attributes, let's check :
        names = []
        for lv in v :
            if isinstance(lv, dict) and "name" in lv.keys():
                names.append(lv["name"])
            else :
                break
        if len(names) == len(v):
            # in cases all values in the list are dict and have a name attribute
            # we replace the original list by the list of names. 
            # meaning we are dropping all other keys, including id and type.
            new_dico[k] = names
            continue

    # in all other cases, we just keep the key value pair as is
    new_dico[k] = v

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