避免在python中将<character写入XML

Question

我试图像这样将这个文本值写入XML标记

 <Parameter name="name"><![CDATA[xyzvalue]]></Parameter>

无论何时，我将此值设置为该标记的文本。它是这样产生的

^{pr2}$

我需要尽量避免代码中出现不可替换的字符

ET.SubElement(parameters, "Parameter", name="id").text = unescape("<![CDATA[xyzvalue]]>")

如何避免它像这样写入xml文件？我需要避免在XML中转义字符。在

这是我的完整代码：

map = ET.Element("Map")

parameters = ET.SubElement(map, "Parameters")
ET.SubElement(parameters, "Parameter", name="bounds").text = "-180,-85.05112877980659,180,85.05112877980659"
ET.SubElement(parameters, "Parameter", name="center").text = "0,0,2"
ET.SubElement(parameters, "Parameter", name="format").text = "png"
ET.SubElement(parameters, "Parameter", name="minzoom").text = "0"
ET.SubElement(parameters, "Parameter", name="maxzoom").text = "22"
ET.SubElement(parameters, "Parameter", name="scale").text = "1"
ET.SubElement(parameters, "Parameter", name="metatile").text = "2"
ET.SubElement(parameters, "Parameter", name="id").text = unescape("<![CDATA[xyzvalue]]>")
ET.SubElement(parameters, "Parameter", name="_updated").text = "1552288036000"
ET.SubElement(parameters, "Parameter", name="name").text = "<![CDATA[xyzvalue]]>"
ET.SubElement(parameters, "Parameter", name="tilejson").text = "<![CDATA[2.0.0]]>"
ET.SubElement(parameters, "Parameter", name="scheme").text = "<![CDATA[xyz]]>"

indent(map)
tree = ET.ElementTree(map)
tree.write("plotfinder_tiles.xml", xml_declaration=True, encoding='utf-8', method="xml")

---

在某种程度上，这与How to output CDATA using ElementTree不同，我在创建元素时遇到了这个问题，不能在创建xml之后对其进行修饰/删除。在

Answer 1

如果是我，我会用lxml's ^{} class。在

但是，如果你想坚持使用ElementTree，你可以在转义之前重新定义ET._escape_cdata，并确保文本不是以<![CDATA[开头，也不是以]]>结尾。在

示例。。。在

Python 3。

import xml.etree.ElementTree as ET


def escape_cdata(text):
    # escape character data
    try:
        if not text.startswith("<![CDATA[") and not text.endswith("]]>"):
            if "&" in text:
                text = text.replace("&", "&amp;")
            if "<" in text:
                text = text.replace("<", "&lt;")
            if ">" in text:
                text = text.replace(">", "&gt;")
        return text
    except (TypeError, AttributeError):
        ET._raise_serialization_error(text)


ET._escape_cdata = escape_cdata

map_elem = ET.Element("Map")

parameters = ET.SubElement(map_elem, "Parameters")
ET.SubElement(parameters, "Parameter", name="bounds").text = "-180,-85.05112877980659,180,85.05112877980659"
ET.SubElement(parameters, "Parameter", name="center").text = "0,0,2"
ET.SubElement(parameters, "Parameter", name="format").text = "png"
ET.SubElement(parameters, "Parameter", name="minzoom").text = "0"
ET.SubElement(parameters, "Parameter", name="maxzoom").text = "22"
ET.SubElement(parameters, "Parameter", name="scale").text = "1"
ET.SubElement(parameters, "Parameter", name="metatile").text = "2"
ET.SubElement(parameters, "Parameter", name="id").text = "<![CDATA[xyzvalue]]>"
ET.SubElement(parameters, "Parameter", name="_updated").text = "1552288036000"
ET.SubElement(parameters, "Parameter", name="name").text = "<![CDATA[xyzvalue]]>"
ET.SubElement(parameters, "Parameter", name="tilejson").text = "<![CDATA[2.0.0]]>"
ET.SubElement(parameters, "Parameter", name="scheme").text = "<![CDATA[xyz]]>"

tree = ET.ElementTree(map_elem)
tree.write("test.xml", xml_declaration=True, encoding='utf-8', method="xml")

XML输出(测试.xml；印刷精美，便于阅读）

^{pr2}$

更新：Python2.7的函数

def escape_cdata(text, encoding):
    # escape character data
    try:
        if not text.startswith("<![CDATA[") and not text.endswith("]]>"):
            if "&" in text:
                text = text.replace("&", "&amp;")
            if "<" in text:
                text = text.replace("<", "&lt;")
            if ">" in text:
                text = text.replace(">", "&gt;")
        return text.encode(encoding, "xmlcharrefreplace")
    except (TypeError, AttributeError):
        ET._raise_serialization_error(text)