pydantic_ai.format_as_xml

format_as_xml

format_as_xml(
    obj: Any,
    root_tag: str = "examples",
    item_tag: str = "example",
    include_root_tag: bool = True,
    none_str: str = "null",
    indent: str | None = "  ",
) -> str

将 Python 对象格式化为 XML。

这很有用，因为大型语言模型 (LLM) 通常发现读取半结构化数据（例如示例）为 XML 比 JSON 等更容易。

支持：str, bytes, bytearray, bool, int, float, date, datetime, Mapping, Iterable, dataclass, 和 BaseModel。

参数

名称	类型	描述	默认值
obj	Any	要序列化为 XML 的 Python 对象。	必需
root_tag	str	用于包裹 XML 的外部标签，使用 None 以省略外部标签。	'examples'
item_tag	str	用于可迭代对象（例如列表）中每个项目的标签，对于数据类和 Pydantic 模型，此标签将被类名覆盖。	'example'
include_root_tag	bool	是否在输出中包含根标签（如果根标签包含主体，则始终包含根标签 - 例如，当输入是简单值时）。	True
none_str	str	用于 None 值的字符串。	'null'
indent	str | None	用于美化打印的缩进字符串。	' '

返回值

类型	描述
str	对象的 XML 表示形式。

示例

format_as_xml_example.py

from pydantic_ai.format_as_xml import format_as_xml

print(format_as_xml({'name': 'John', 'height': 6, 'weight': 200}, root_tag='user'))
'''
<user>
  <name>John</name>
  <height>6</height>
  <weight>200</weight>
</user>
'''

pydantic_ai_slim/pydantic_ai/format_as_xml.py 中的源代码

def format_as_xml(
    obj: Any,
    root_tag: str = 'examples',
    item_tag: str = 'example',
    include_root_tag: bool = True,
    none_str: str = 'null',
    indent: str | None = '  ',
) -> str:
    """Format a Python object as XML.

    This is useful since LLMs often find it easier to read semi-structured data (e.g. examples) as XML,
    rather than JSON etc.

    Supports: `str`, `bytes`, `bytearray`, `bool`, `int`, `float`, `date`, `datetime`, `Mapping`,
    `Iterable`, `dataclass`, and `BaseModel`.

    Args:
        obj: Python Object to serialize to XML.
        root_tag: Outer tag to wrap the XML in, use `None` to omit the outer tag.
        item_tag: Tag to use for each item in an iterable (e.g. list), this is overridden by the class name
            for dataclasses and Pydantic models.
        include_root_tag: Whether to include the root tag in the output
            (The root tag is always included if it includes a body - e.g. when the input is a simple value).
        none_str: String to use for `None` values.
        indent: Indentation string to use for pretty printing.

    Returns:
        XML representation of the object.

    Example:
    ```python {title="format_as_xml_example.py" lint="skip"}
    from pydantic_ai.format_as_xml import format_as_xml

    print(format_as_xml({'name': 'John', 'height': 6, 'weight': 200}, root_tag='user'))
    '''
    <user>
      <name>John</name>
      <height>6</height>
      <weight>200</weight>
    </user>
    '''
    ```
    """
    el = _ToXml(item_tag=item_tag, none_str=none_str).to_xml(obj, root_tag)
    if not include_root_tag and el.text is None:
        join = '' if indent is None else '\n'
        return join.join(_rootless_xml_elements(el, indent))
    else:
        if indent is not None:
            ElementTree.indent(el, space=indent)
        return ElementTree.tostring(el, encoding='unicode')