Question

I have s special xml file like below:

<alarm-dictionary source="DDD" type="ProxyComponent">

    <alarm code="402" severity="Alarm" name="DDM_Alarm_402">
    <message>Database memory usage low threshold crossed</message>
    <description>dnKinds = database
    type = quality_of_service
    perceived_severity = minor
    probable_cause = thresholdCrossed
    additional_text = Database memory usage low threshold crossed
    </description>
    </alarm>

        ...
</alarm-dictionary>

I know in python, I can get the “alarm code”, “severity” in tag alarm by:

for alarm_tag in dom.getElementsByTagName('alarm'):
    if alarm_tag.hasAttribute('code'):
        alarmcode = str(alarm_tag.getAttribute('code'))

And I can get the text in tag message like below:

for messages_tag in dom.getElementsByTagName('message'):
    messages = ""
    for message_tag in messages_tag.childNodes:
        if message_tag.nodeType in (message_tag.TEXT_NODE, message_tag.CDATA_SECTION_NODE):
            messages += message_tag.data

But I also want to get the value like dnkind(database), type(quality_of_service), perceived_severity(thresholdCrossed) and probable_cause(Database memory usage low threshold crossed
) in tag description.

That is, I also want to parse the content in the tag in xml.

Could anyone help me with this?
Thanks a lot!

Answer 1

Once you have the text from the description tag, it’s nothing to do with XML parsing. You just need do simple string-parsing to get the type = quality_of_service keys/values strings into something nicer to use in Python like a dictionary

With some slightly simpler parsing thanks to ElementTree, it would look like this

messages = """
<alarm-dictionary source="DDD" type="ProxyComponent">

    <alarm code="402" severity="Alarm" name="DDM_Alarm_402">
    <message>Database memory usage low threshold crossed</message>
    <description>dnKinds = database
    type = quality_of_service
    perceived_severity = minor
    probable_cause = thresholdCrossed
    additional_text = Database memory usage low threshold crossed
    </description>
    </alarm>

        ...
</alarm-dictionary>
"""

import xml.etree.ElementTree as ET

# Parse XML
tree = ET.fromstring(messages)

for alarm in tree.getchildren():
    # Get code and severity
    print alarm.get("code")
    print alarm.get("severity")

    # Grab description text
    descr = alarm.find("description").text

    # Parse "thing=other" into dict like {'thing': 'other'}
    info = {}
    for dl in descr.splitlines():
        if len(dl.strip()) > 0:
            key, _, value = dl.partition("=")
            info[key.strip()] = value.strip()
    print info