如何将我的嵌套结构写成字符串列表而不是字符串列表？

def convert_to_string_list(nested_structure):
    result = []
    
    # 如果是字符串，则直接加入结果列表
    if isinstance(nested_structure, str):
        result.append(nested_structure)
    
    # 如果是列表，则递归处理列表中的每个元素
    elif isinstance(nested_structure, list):
        for item in nested_structure:
            result += convert_to_string_list(item)
    
    # 如果是字典，则递归处理字典的值
    elif isinstance(nested_structure, dict):
        for value in nested_structure.values():
            result += convert_to_string_list(value)
    
    return result

nested_structure = ["hello", ["world", {"foo": "bar"}], "example"]
string_list = convert_to_string_list(nested_structure)
print(string_list)

['hello', 'world', 'bar', 'example']