在 python 中添加新的 XML 节点和漂亮的打印 XML

Question

我可以使用 ElementTree 添加 XML 节点，但是当我以文本格式打开 xml 文件时，这会在一行中返回输出，而不是树结构。我也尝试使用 minidom.toprettyxml 但我不知道如何将输出添加到原始 XML。由于我希望脚本在其他环境中可重现，因此我不喜欢使用 lxml 等外部库。有人可以帮助我如何漂亮地打印输出吗？ - 蟒蛇2.7

示例 XML。这就是它在文本格式和资源管理器中的外观。

<?xml version="1.0" encoding="utf-8"?>
<default_locators >
  <locator_ref>
    <name>cherry</name>
    <display_name>cherrycherry</display_name>
    <workspace_properties>
      <factory_progid>Workspace</factory_progid>
      <path>InstallDir</path>
    </workspace_properties>
  </locator_ref>
</default_locators>

文本格式和资源管理器的预期输出。

<?xml version="1.0" encoding="utf-8"?>
<default_locators >
  <locator_ref>
    <name>cherry</name>
    <display_name>cherrycherry</display_name>
    <workspace_properties>
      <factory_progid>Workspace</factory_progid>
      <path>InstallDir</path>
    </workspace_properties>
  </locator_ref>
  <locator_ref>
    <name>berry</name>
    <display_name>berryberry</display_name>
    <workspace_properties>
      <factory_progid>Workspace</factory_progid>
      <path>C:\temp\temp</path>
    </workspace_properties>
  </locator_ref>
</default_locators>

我的脚本

#coding: cp932

import xml.etree.ElementTree as ET

tree = ET.parse(r"C:\DefaultLocators.xml")
root = tree.getroot()

locator_ref = ET.SubElement(root, "locator_ref")
name = ET.SubElement(locator_ref, "name")
name.text = " berry"
display_name = ET.SubElement(locator_ref, "display_name")
display_name.text = "berryberry"
workspace_properties = ET.SubElement(locator_ref, "workspace_properties")
factory_progid = ET.SubElement(workspace_properties,"factory_progid")
factory_progid.text = "Workspace"
path = ET.SubElement(workspace_properties, "path")
path.text = r"c:\temp\temp"

tree.write(r"C:\DefaultLocators.xml", encoding='utf-8')

返回的输出。运行我的脚本后，新节点被添加到我的 sample.xml 文件中，但它在一行中返回输出，所有换行符和缩进都从原始 sample.xml 文件中删除。至少当我以文本格式打开 sample.xml 文件时它是这样的。但是，当我在资源管理器中打开 sample.xml 文件时，它看起来很好。我仍然像以前一样看到换行符和缩进。即使在运行脚本后，如何将原始树结构保持为文本格式？

<default_locators>
  <locator_ref>
    <name>cherry</name>
    <display_name>cherrycherry</display_name>
    <workspace_properties>
      <factory_progid>Workspace</factory_progid>
      <path>InstallDir</path>
    </workspace_properties>
  </locator_ref>
<locator_ref><name> berry</name><display_name>berryberry</display_name><workspace_properties><factory_progid>Workspace</factory_progid><path>c:\temp\temp</path></workspace_properties></locator_ref></default_locators>

Answer 1

在处理元素时，你可以这样做：element.tail = '\n' 然后，它将被写成一行。

Answer 2

在 elementTree 中写你的 xml 为：

import xml.etree.ElementTree as ET


def serialize_xml(write, elem, encoding, qnames, namespaces):
    tag = elem.tag
    text = elem.text
    if tag is ET.Comment:
        write("<!--%s-->" % _encode(text, encoding))
    elif tag is ET.ProcessingInstruction:
        write("<?%s?>" % _encode(text, encoding))
    else:
        tag = qnames[tag]
        if tag is None:
            if text:
                write(_escape_cdata(text, encoding))
            for e in elem:
                serialize_xml(write, e, encoding, qnames, None)
        else:
            write("\n<" + tag) ## '\n' added by namit
            items = elem.items()
            if items or namespaces:
                if namespaces:
                    for v, k in sorted(namespaces.items(),
                                       key=lambda x: x[1]):  # sort on prefix
                        if k:
                            k = ":" + k
                        write(" xmlns%s=\"%s\"" % (
                            k.encode(encoding),
                            _escape_attrib(v, encoding)
                            ))
                for k, v in sorted(items):  # lexical order
                    if isinstance(k, QName):
                        k = k.text
                    if isinstance(v, QName):
                        v = qnames[v.text]
                    else:
                        v = _escape_attrib(v, encoding)
                    write(" %s=\"%s\"" % (qnames[k], v))
            if text or len(elem):
                write(">")
                if text:
                    write(ET._escape_cdata(text, encoding))
                for e in elem:
                    serialize_xml(write, e, encoding, qnames, None)
                write("</" + tag + ">")
            else:
                write(" />")
    if elem.tail:
        write(ET._escape_cdata(elem.tail, encoding))

ET._serialize_xml=serialize_xml

tree = ET.parse(r"samplexml.xml")
root = tree.getroot()

locator_ref = ET.SubElement(root, "locator_ref")
name = ET.SubElement(locator_ref, "name")
name.text = " berry"
display_name = ET.SubElement(locator_ref, "display_name")
display_name.text = "berryberry"
workspace_properties = ET.SubElement(locator_ref, "workspace_properties")
factory_progid = ET.SubElement(workspace_properties,"factory_progid")
factory_progid.text = "WorkspaceFactory"
path = ET.SubElement(workspace_properties, "path")

ins_out=open("samplexml_1.xml",'wb',1000)
ET.ElementTree(locator_ref).write(ins_out,encoding="ASCII")
ins_out.close()

这将在单行中写入完整的文件；无需在 xml 尾部添加空格。

Answer 3

我认为您必须尝试lxml library。这是在 Python 中解析 XML 的最佳方式。 对于这些事情，它有神奇的参数 *pretty_print*。 这是一个例子：

import lxml.etree as etree

root = etree.Element("root")
for rn in range(10):
    etree.SubElement(root, "column_%s" % str(rn)).text = str(rn*rn)
pretty_data = etree.tostring(root, pretty_print=True, encoding = 'utf-8')
print final_data

结果：http://pastebin.com/y0rkQ78G