LXML树连接和属性

Question

我有一个.dtsx文件，因此，我有多个具有连接的组件，因此我需要提取具有特殊连接的组件，但是我无法处理，例如：

<components>
    <component refId="Component_1 Name" componentClassID="componentClassID" contactInfo="contactInfo" description="description" name="name" usesDispositions="true" version="6">
        <properties>
            <property dataType="System.String" description="description" expressionType="Notify" name="SqlCommandParam" UITypeEditor="UITypeEditor">QUERY THAT i NEED TO GET</property>
        </properties>
        <connections>
            <connection refId="Name" connectionManagerID="Package.ConnectionManagers[BI_SYNC]" connectionManagerRefId="Package.ConnectionManagers[BI_SYNC]" description="description" name="OleDbConnection" />
        </connections>
    </component>
    <component refId="Component_2 Name" componentClassID="componentClassID" contactInfo="contactInfo" description="description" name="PartnerService" usesDispositions="true" version="6">
        <properties>
            <property dataType="System.String" description="description" expressionType="Notify" name="SqlCommandParam" UITypeEditor="UITypeEditor">QUERY THAT I DONT NEED TO GET</property>
        </properties>
        <connections>
            <connection refId="Name" connectionManagerID="Package.ConnectionManagers[BI_STG]" connectionManagerRefId="Package.ConnectionManagers[BI_STG]" description="description" name="OleDbConnection" />
        </connections>
    </component>
</components>

我需要获取查询，其中< 相同级别，属性和连接代码为+/- like：

代码> ConnectionManagerId =“ package.connectionManagers [bi_sync]” ，但我无法处理，因为它们处于我使用的

for cnt, element in enumerate(root.xpath(".//*")):
    if cnt == 0:
        file = root.attrib["{www.microsoft.com/SqlServer/Dts}ObjectName"]
        data["file_name"] = file + ".dtsx"
    if element.tag == con_tag:
        if element.attrib.get("{www.microsoft.com/SqlServer/Dts}ObjectName"):
            if element.attrib.get("{www.microsoft.com/SqlServer/Dts}ObjectName", None) == "BI_SYNC":
                conn_name = element.attrib.get("{www.microsoft.com/SqlServer/Dts}ObjectName", None)
                conn_dtsid = element.attrib.get("{www.microsoft.com/SqlServer/Dts}DTSID", None)
                data["conn_name"] = conn_name
                data["conn_dtsid"] = conn_dtsid
    if element.tag == exec_tag:
        for cnt_0, element_0 in enumerate(element):
            if element_0.tag == execs_tag:
                for cnt_1, element_1 in enumerate(element_0): # Get package name

Answer 1

由于属性和连接都是相同component的孩子，因此您可以使用XPath选择基于component基于连接，然后选择属性。

因此，请尝试使用类似的内容，而不是在陈述中嵌套很多，

from lxml import etree

xml = """<root xmlns="www.microsoft.com/SqlServer/Dts">
    <components>
        <component refId="Component_1 Name" componentClassID="componentClassID" contactInfo="contactInfo" description="description" name="name" usesDispositions="true" version="6">
            <properties>
                <property dataType="System.String" description="description" expressionType="Notify" name="SqlCommandParam" UITypeEditor="UITypeEditor">QUERY THAT i NEED TO GET</property>
            </properties>
            <connections>
                <connection refId="Name" connectionManagerID="Package.ConnectionManagers[BI_SYNC]" connectionManagerRefId="Package.ConnectionManagers[BI_SYNC]" description="description" name="OleDbConnection"/>
            </connections>
        </component>
        <component refId="Component_2 Name" componentClassID="componentClassID" contactInfo="contactInfo" description="description" name="PartnerService" usesDispositions="true" version="6">
            <properties>
                <property dataType="System.String" description="description" expressionType="Notify" name="SqlCommandParam" UITypeEditor="UITypeEditor">QUERY THAT I DONT NEED TO GET</property>
            </properties>
            <connections>
                <connection refId="Name" connectionManagerID="Package.ConnectionManagers[BI_STG]" connectionManagerRefId="Package.ConnectionManagers[BI_STG]" description="description" name="OleDbConnection"/>
            </connections>
        </component>
    </components>
</root>
"""

root = etree.fromstring(xml)

ns = {"dts": "www.microsoft.com/SqlServer/Dts"}

for property_elem in root.xpath(".//dts:component[dts:connections/dts:connection[@connectionManagerID='Package.ConnectionManagers[BI_SYNC]']]/dts:properties/dts:property", namespaces=ns):
    print(etree.tostring(property_elem).decode())

这会输出以下内容，以表明它选择了正确的属性 ...

<property xmlns="www.microsoft.com/SqlServer/Dts" dataType="System.String" description="description" expressionType="Notify" name="SqlCommandParam" UITypeEditor="UITypeEditor">QUERY THAT i NEED TO GET</property>

有几个注释...

• 我添加了一个root带有默认命名空间的元素，因此我的root变量将与您已经拥有的变量相似。
• 我使用命名空间 kwarg，因此我可以在XPATH中使用前缀，而不是使用Clark符号。 （我认为更清洁。）