I need to admit, when I initiated and released ruledxml for the first time, I didn’t care much about namespaces. The usecase was not prevalent in my setting. This changed now.
Time to implement it properly and so I need to look at handling XML namespaces with python’s lxml.etree in more detail. In the following you can see a cheatsheet how you achieve a certain XML namespaced output with lxml.etree.Element instances.
The following table always shows a desired result following by the python source code to generate it.
<a><b/></a> |
|---|
>>> a = lxml.etree.Element('a')
>>> b = lxml.etree.Element('b')
>>> a.append(b)
>>> lxml.etree.tostring(a)
b'<a><b/></a>'
|
<a xmlns="http://example.org/"> <b/> </a> |
>>> a = lxml.etree.Element('a', nsmap={None: 'http://example.org/'})
>>> b = lxml.etree.Element('b')
>>> a.append(b)
>>> lxml.etree.tostring(a)
b'<a xmlns="http://example.org/"><b/></a>'
|
<a xmlns:ex="http://example.org/"> <ex:b/> </a> |
>>> a = lxml.etree.Element('a',
... nsmap={'ex': 'http://example.org/'})
>>> b = e('{http://example.org/}b')
>>> a.append(b)
>>> lxml.etree.tostring(a)
b'<a xmlns:ex="http://example.org/"><ex:b/></a>'
|
<ex:a xmlns:ex="http://example.org/"> <ex:b/> </ex:a> |
>>> a = lxml.etree.Element('{http://example.org/}a',
... nsmap={'ex': 'http://example.org/'})
>>> b = e('{http://example.org/}b')
>>> a.append(b)
>>> lxml.etree.tostring(a)
b'<ex:a xmlns:ex="http://example.org/"><ex:b/></ex:a>'
|
<ex:a xmlns:ex="http://example.org/" ex:attr="value"> <ex:b/> </ex:a> |
>>> a = lxml.etree.Element('{http://example.org/}a',
... nsmap={'ex': 'http://example.org/'})
>>> a.attrib['{http://example.org/}attr'] = 'value'
>>> a.append(b)
>>> lxml.etree.tostring(a)
b'<ex:a xmlns:ex="http://example.org/"
ex:attr="value"><ex:b/></ex:a>'
|
<ex:a xmlns:ex="http://example.org/example"
xmlns:org="http://example.org/organization"
ex:attr="value">
<org:b ex:example="value1" org:example="value2"/>
</ex:a>
|
>>> a = lxml.etree.Element('{http://example.org/example}a',
... nsmap={'ex': 'http://example.org/example',
... 'org': 'http://example.org/organization'})
>>> a.attrib['{http://example.org/example}attr'] = 'value'
>>> b = lxml.etree.Element('{http://example.org/organization}b')
>>> b.attrib['{http://example.org/example}example'] = 'value1'
>>> b.attrib['{http://example.org/organization}example'] = 'value2'
>>> a.append(b)
>>> lxml.etree.tostring(a)
b'<ex:a xmlns:ex="http://example.org/example"
xmlns:org="http://example.org/organization"
ex:attr="value">
<org:b ex:example="value1" org:example="value2"/></ex:a>'
|
<a xmlns:ex="http://example.org/" xml:lang="ja"> <ex:b/> </a> |
>>> a = lxml.etree.Element('a',
... nsmap={'ex': 'http://example.org/'})
>>> a.attrib["{http://www.w3.org/XML/1998/namespace}lang"] = 'ja'
>>> b = lxml.etree.Element('{http://example.org/}b')
>>> a.append(b)
>>> lxml.etree.tostring(a)
b'<a xmlns:ex="http://example.org/" xml:lang="ja"><ex:b/></a>'
|
<a xmlns:ex="http://example.org/" xml:lang="ja"> <ex:b xml:lang="en"/> </a> |
>>> a = lxml.etree.Element('a',
... nsmap={'ex': 'http://example.org/'})
>>> a.attrib["{http://www.w3.org/XML/1998/namespace}lang"] = 'ja'
>>> b = lxml.etree.Element('{http://example.org/}b')
>>> b.attrib["{http://www.w3.org/XML/1998/namespace}lang"] = 'en'
>>> a.append(b)
>>> lxml.etree.tostring(a)
b'<a xmlns:ex="http://example.org/" xml:lang="ja"><ex:b
xml:lang="en"/></a>'
|