如何使用lxml针对多个xsd模式进行验证? [英] How do I validate against multiple xsd schemas using lxml?

问题描述

我正在编写一个单元测试，该单元测试将通过获取其xsd模式并使用python的lxml库进行验证来验证生成的站点地图xml:

I'm writing a unit test that validates sitemap xml I generate by fetching its xsd schema and validating using python's lxml library:

在我的根元素上有一些元数据:

Here's some metadata on my root element:

xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"
xmlns:image="http://www.google.com/schemas/sitemap-image/1.1"
xsi:schemaLocation="http://www.sitemaps.org/schemas/sitemap/0.9 
http://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd 
http://www.google.com/schemas/sitemap-image/1.1 
http://www.google.com/schemas/sitemap-image/1.1/sitemap-image.xsd"

此测试代码:

_xsd_validators = {}
def get_xsd_validator(url):
    if url not in _xsd_validators:
        _xsd_validators[url] = etree.XMLSchema(etree.parse(StringIO(requests.get(url).content)))
    return _xsd_validators[url]


# this util function is later on in a TestCase
def validate_xml(self, content):
    content.seek(0)
    doc = etree.parse(content)
    schema_loc = doc.getroot().attrib.get('{http://www.w3.org/2001/XMLSchema-instance}schemaLocation').split(' ')
    # lxml doesn't like multiple namespaces
    for i, loc in enumerate(schema_loc):
        if i % 2 == 1:
            get_xsd_validator(schema_loc[i]).assertValid(doc)
    return doc

示例XML验证失败:

<?xml version="1.0" encoding="UTF-8"?>
<urlset
  xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"
  xmlns:image="http://www.google.com/schemas/sitemap-image/1.1"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="
    http://www.sitemaps.org/schemas/sitemap/0.9
    http://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd
    http://www.google.com/schemas/sitemap-image/1.1
    http://www.google.com/schemas/sitemap-image/1.1/sitemap-image.xsd"
>
  <url>
    <loc>https://www.example.com/press</loc>
    <lastmod>2016-08-11</lastmod>

    <changefreq>weekly</changefreq>
  </url>

  <url>
    <loc>https://www.example.com/about-faq</loc>
    <lastmod>2016-08-11</lastmod>

    <changefreq>weekly</changefreq>
  </url>


</urlset>

当我只有一个常规站点地图时，一切都很好，但是当我添加图像站点地图标记时，assertValid开始失败:

When I just had a regular sitemap everything worked great, but when I added in image sitemap markup assertValid started failing with:

E   DocumentInvalid: Element '{http://www.google.com/schemas/sitemap-image/1.1}image': No matching global element declaration available, but demanded by the strict wildcard., line 12

或者:

E   DocumentInvalid: Element '{http://www.sitemaps.org/schemas/sitemap/0.9}urlset': No matching global declaration available for the validation root., line 6

推荐答案

您可以尝试定义一个包装器架构 wrapper-schema.xsd ，该架构器导入所有需要的架构，并将该架构与lxml结合使用而不是其他每个人.

You could try to define a wrapper schema wrapper-schema.xsd that imports all the schemas needed, and use this schema with lxml instead of each one of the others.

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:import
    namespace="http://www.sitemaps.org/schemas/sitemap/0.9"
    schemaLocation="http://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd"/>
  <xs:import
    namespace="http://www.google.com/schemas/sitemap-image/1.1"
    schemaLocation="http://www.google.com/schemas/sitemap-image/1.1/sitemap-image.xsd"/>
</xs:schema>

我没有python，但这可以在oXygen中成功验证:

I don't have python, but this validates successfully in oXygen:

<?xml version="1.0" encoding="UTF-8"?>
<urlset  xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"
    xmlns:image="http://www.google.com/schemas/sitemap-image/1.1"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:noNamespaceSchemaLocation="wrapper-schema.xsd"
    >
    <image:image>
        <image:loc>http://www.example.com/image</image:loc>
    </image:image>
    <url>
        <loc>https://www.example.com/press</loc>
        <lastmod>2016-08-11</lastmod>
        <changefreq>weekly</changefreq>
    </url>
    <url>
        <loc>https://www.example.com/about-faq</loc>
        <lastmod>2016-08-11</lastmod>
        <changefreq>weekly</changefreq>
    </url>
</urlset>

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