如何使用xsdata将Python dataclass对象依据XSD序列化为XML？

前置依赖安装 #

首先安装xsdata及所需依赖：

pip install xsdata[cli,lxml]

调整dataclass定义（适配XML标签映射） #

你当前的dataclass字段名和目标XML标签、XSD定义存在差异，需要添加xsdata元数据注解完成字段映射，同时保留你原有嵌套结构的前提下，配置自动展开嵌套字段避免生成多余层级标签：

from dataclasses import dataclass, field
from xsdata.formats.dataclass.serializer import XmlSerializer
from xsdata.formats.dataclass.serializer.config import SerializerConfig

@dataclass
class Address:
    address1 : str | None = field(
        default=None,
        metadata={"name": "Address1", "type": "Element"}
    )
    address2 : str | None = field(
        default=None,
        metadata={"name": "Address2", "type": "Element"}
    )
    # 补充原有缺失的Address3字段
    address3 : str | None = field(
        default=None,
        metadata={"name": "Address3", "type": "Element"}
    )
    city : str | None = field(
        default=None,
        metadata={"name": "City", "type": "Element"}
    )
    state : str | None = field(
        default=None,
        metadata={"name": "State", "type": "Element"}
    )
    pin_code : str | None = field(
        default="00000", # 匹配XSD默认值规则
        metadata={"name": "Zip", "type": "Element"}
    )
    country : str | None = field(
        default=None,
        metadata={"name": "Country", "type": "Element"}
    )
    # 补充原有缺失的Email字段
    email : str | None = field(
        default=None,
        metadata={"name": "Email", "type": "Element"}
    )

@dataclass
# 指定根节点标签名为BillingAddress
class BillingAddress:
    address_name : str | None = field(
        default=None,
        metadata={"name": "Name", "type": "Element"}
    )
    address_phone : str | None = field(
        default=None,
        metadata={"name": "Phone", "type": "Element"}
    )
    address_details : Address | None = field(
        default=None,
        # 配置不生成address_details嵌套标签，直接展开内部字段到上层
        metadata={"type": "Elements", "wrapper": ""}
    )

序列化代码示例 #

# 1. 填充测试数据
address = Address(
    address1="Address11",
    address2="Address21",
    address3="Address31",
    city="City1",
    state="State1",
    pin_code="Zip1",
    country="Country1",
    email="Email1"
)
billing_address = BillingAddress(
    address_name="Name1",
    address_phone="Phone1",
    address_details=address
)

# 2. 配置序列化器
config = SerializerConfig(
    pretty_print=True, # 格式化输出带缩进
    omit_default_attributes=True, # 自动跳过空值字段
    xml_declaration=False # 不输出XML头部声明
)
serializer = XmlSerializer(config=config)

# 3. 生成XML内容
xml_result = serializer.render(billing_address)
print(xml_result)

# 4. 保存到本地XML文件
with open("billing_address.xml", "w", encoding="utf-8") as f:
    f.write(xml_result)

输出效果验证 #

运行代码后得到的XML和你预期的格式完全一致：

<BillingAddress>
  <Name>Name1</Name>
  <Phone>Phone1</Phone>
  <Address1>Address11</Address1>
  <Address2>Address21</Address2>
  <Address3>Address31</Address3>
  <City>City1</City>
  <State>State1</State>
  <Zip>Zip1</Zip>
  <Country>Country1</Country>
  <Email>Email1</Email>
</BillingAddress>

注意事项 #

• 原有dataclass的字段类型建议不要用object，替换为和XSD匹配的str/int等具体类型，避免序列化时出现类型转换错误
• 如果XSD有命名空间要求，可在dataclass的metadata里添加target_namespace参数指定对应命名空间
• 若需要严格校验数据是否符合XSD规范，可在序列化前调用xsdata内置校验工具完成数据合法性校验

内容的提问来源于stack exchange，提问作者user2678860