pyxb UnrecognizedDOMRootNodeError

问题

i've got the following xml schema:

<xsd:schema attributeFormDefault="unqualified" elementFormDefault="qualified" xmlns:xsd="http://www.w3.org/2001/XMLSchema">

<xsd:complexType name="DataPackage">
    <xsd:sequence>
        <xsd:element name="timestamp" type="xsd:float" default="0.0"/>
        <xsd:element name="type" type="xsd:string" default="None"/>
        <xsd:element name="host" type="xsd:string" default="None"/>
        <xsd:element name="data" type="Data" />
    </xsd:sequence>
</xsd:complexType>

<xsd:complexType name="Data">
    <xsd:sequence>
        <xsd:element name="item" type="Item" minOccurs="0" maxOccurs="unbounded" />
    </xsd:sequence>
</xsd:complexType>

<xsd:complexType name="Item">
    <xsd:sequence>
        <xsd:element name="key" type="xsd:string"/>
        <xsd:element name="val" type="xsd:string"/>
    </xsd:sequence>
 </xsd:complexType>

</xsd:schema>

I used pyxbgen -u DataPackage.xsd -m DataPackage to generate the corresponding python classes and used these to generate the following xml code:

<?xml version="1.0" encoding="utf-8"?>
<DataPackage>
<timestamp>1378970933.29</timestamp>
<type>None</type>
<host>Client 1</host>
<data>
    <item>
        <key>KEY1</key>
        <val>value1</val>
    </item>
</data>
</DataPackage>

If i try to read this using the following in python interpreter:

import DataPackage
xml = file("dataPackage-Test.xml").read()
data = DataPackage.CreateFromDocument(xml)

I get the exception:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "DataPackage.py", line 54, in CreateFromDocument
    instance = handler.rootObject()
  File "/usr/local/lib/python2.7/dist-packages/pyxb/binding/saxer.py", line 274, in   rootObject
    raise pyxb.UnrecognizedDOMRootNodeError(self.__rootObject)
pyxb.exceptions_.UnrecognizedDOMRootNodeError: <pyxb.utils.saxdom.Element object at  0x9c7c76c>

Anyone an idea what's wrong?

回答1:

Your schema defines a top-level complex type named DataPackage, but does not define any top-level elements. Thus the DOM element DataPackage has no corresponding element that PyXB can use to process it.

You need to add something like:

<element name="DataPackage" type="DataPackage"/>

Note that in XML Schema the namespaces for elements and types are distinct, but in Python they are not, so PyXB will rename one of them (the complex type in this case) to avoid the conflict. See http://pyxb.sourceforge.net/arch_binding.html?highlight=conflict#deconflicting-names

来源：https://stackoverflow.com/questions/18758240/pyxb-unrecognizeddomrootnodeerror

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