Python-сообщество

 <?xml version="1.0" encoding="UTF-8"?>
    <AirShoppingRS Version="16.2" xsi:schemaLocation="http://www.iata.org/IATA/EDIST AirShoppingRS.xsd"
        xmlns="http://www.iata.org/IATA/EDIST"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <Document/>
        <Success/>
        <ShoppingResponseID>
            <ResponseID>2017-10-04T14:35:25.243504</ResponseID>
        </ShoppingResponseID>
        <OffersGroup>
            <AirlineOffers>
                <TotalOfferQuantity>297</TotalOfferQuantity>
                <Owner>SU</Owner>
                <AirlineOffer>
                    <OfferID Owner="SU">OFFER5</OfferID>
                    <TotalPrice>
                        <SimpleCurrencyPrice Code="RUB">36229</SimpleCurrencyPrice>
                    </TotalPrice>
                    <PricedOffer>
                        <OfferPrice OfferItemID="5">
                            <RequestedDate>
                                <PriceDetail>
                                    <TotalAmount>
                                        <SimpleCurrencyPrice>36229</SimpleCurrencyPrice>
                                    </TotalAmount>
                                    <BaseAmount>33000</BaseAmount>
                                    <Taxes>
                                        <Total Code="RUB">3229</Total>
                                    </Taxes>
                                </PriceDetail>
                            </RequestedDate>
                            <FareDetail>
                                <FareComponent>
                                    <SegmentReference>SEG_SVOLED_1</SegmentReference>
                                    <FareBasis>
                                        <FareBasisCode>
                                            <Code>DFOR</Code>
                                        </FareBasisCode>
                                    </FareBasis>
                                </FareComponent>
                            </FareDetail>
                        </OfferPrice>
                    </PricedOffer>
                </AirlineOffer>
            </AirlineOffers>
        </OffersGroup>
    </AirShoppingRS>

         root = etree.fromstring(xml.content)
        airline_offers = root.find("ShoppingResponseID")

 root.find("ShoppingResponseID", namespaces={None: 'http://www.iata.org/IATA/EDIST'})