xml.dom.minidom does not support default namespaces

[crass]

BPO	13102
Nosy	@jkloth, @ezio-melotti
Files	test.py: Illustrative test case

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = None
closed_at = <Date 2014-06-20.02:35:52.127>
created_at = <Date 2011-10-04.20:11:53.454>
labels = ['expert-XML', 'type-bug', 'invalid']
title = 'xml.dom.minidom does not support default namespaces'
updated_at = <Date 2014-06-20.02:35:52.127>
user = 'https://bugs.python.org/crass'

bugs.python.org fields:

activity = <Date 2014-06-20.02:35:52.127>
actor = 'ezio.melotti'
assignee = 'none'
closed = True
closed_date = <Date 2014-06-20.02:35:52.127>
closer = 'ezio.melotti'
components = ['XML']
creation = <Date 2011-10-04.20:11:53.454>
creator = 'crass'
dependencies = []
files = ['23313']
hgrepos = []
issue_num = 13102
keywords = []
message_count = 3.0
messages = ['144924', '144927', '221026']
nosy_count = 4.0
nosy_names = ['jkloth', 'ezio.melotti', 'BreamoreBoy', 'crass']
pr_nums = []
priority = 'normal'
resolution = 'not a bug'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue13102'
versions = ['Python 2.6', 'Python 2.7']

[crass]

When using getAttributeNS, attributes with no namespace should be considered as having the default namespace for that scope. See examples in http://www.w3.org/TR/REC-xml-names/#defaulting. Python's xml.dom.minidom will always set the namespace to None for attributes that have no namespace prefix.

I've attached a test program to illustrate this issue in action. The output I get is:
[((None, u'attr'), u'value1')]
[(('http://www.w3.org/2000/xmlns/', 'xmlns'), u'http://path/to/ns2#'), ((None, u'attr'), u'value2')]
[((u'http://path/to/ns2#', u'attr'), u'value3')]
Successfully got child3 attr value

In the first two cases the namespaceURI is None, but it should be set to the default namespace specified in the root element. I believe this problem occurs with all *NS functions. Not tested in 3.x.

[jkloth]

Please read the link which you posted. Quoting the second paragraph, second sentence:

"Default namespace declarations do not apply directly to attribute names;"

and from the third paragraph, third sentence:

"The namespace name for an unprefixed attribute name always has no value."

Therefore minidom *is* conformant by having None as the namespace-uri for unprefixed attribute names.

[BreamoreBoy]

From the statement in msg144927 this can be closed as "not a bug".