Element Tree: How to parse subElements of child nodes

Question

I have an XML tree, which I'd like to parse using Elementtree. My XML looks something like

<?xml version="1.0" encoding="UTF-8"?>
<GetOrdersResponse xmlns="urn:ebay:apis:eBLBaseComponents">
<Ack>Success</Ack>
<Version>857</Version>
<Build>E857_INTL_APIXO_16643800_R1</Build>
<PaginationResult>
    <TotalNumberOfPages>1</TotalNumberOfPages>
    <TotalNumberOfEntries>2</TotalNumberOfEntries>
</PaginationResult>
<HasMoreOrders>false</HasMoreOrders>
<OrderArray>
    <Order>
        <OrderID>221362908003-1324471823012</OrderID>
        <CheckoutStatus>
            <eBayPaymentStatus>NoPaymentFailure</eBayPaymentStatus>
            <LastModifiedTime>2014-02-03T12:08:51.000Z</LastModifiedTime>
            <PaymentMethod>PaisaPayEscrow</PaymentMethod>
            <Status>Complete</Status>
            <IntegratedMerchantCreditCardEnabled>false</IntegratedMerchantCreditCardEnabled>
        </CheckoutStatus>
    </Order>
    <Order> ...
    </Order>
    <Order> ...
    </Order>
</OrderArray>
</GetOrdersResponse>

I want to parse the 6th child of the XML () I am able to get the value of subelements by index. E.g if I want OrderID of first order, i can use root[5][0][0].text. But, I would like to get the values of subElements by name. I tried the following code, but it does not print anything:

tree = ET.parse('response.xml')
root = tree.getroot()
for child in root:
    try:
        for ids in child.find('Order').find('OrderID'):
            print ids.text
    except:
        continue

Could someone please help me on his. Thanks

Answer 1

Since the XML document has a namespace declaration (xmlns="urn:ebay:apis:eBLBaseComponents"), you have to use universal names when referring to elements in the document. For example, you need {urn:ebay:apis:eBLBaseComponents}OrderID instead of just OrderID.

This snippet prints all OrderIDs in the document:

from xml.etree import ElementTree as ET

NS = "urn:ebay:apis:eBLBaseComponents"

tree = ET.parse('response.xml')

for elem in tree.iter("*"):    # Use tree.getiterator("*") in Python 2.5 and 2.6
    if elem.tag == '{%s}OrderID' % NS:
        print elem.text

See http://effbot.org/zone/element-namespaces.htm for details about ElementTree and namespaces.

Answer 2

Try to avoid chaining your finds. If your first find does not find anything, it will return None.

for child in root:
    order = child.find('Order')
    if order is not None:
        ids = order.find('OrderID')
        print ids.text

Answer 3

You can find an OrderArray first and then just iterate its children by name:

tree = ET.parse('response.xml')
root = tree.getroot()
order_array = root.find("OrderArray")
for order in order_array.findall('Order'):
    order_id_element = order.find('OrderID')
    if order_id_element is not None:
        print order_id_element.text

A side note. Never ever use except: continue. It hides any exception you get and makes debugging really hard.