lxml or other library parsing nested xml with xpath
<p>I have XML of the following structure:</p>

<pre><code>&lt;SEC-DOCUMENT&gt;0001209191-16-145281.txt : 20161006
&lt;SEC-HEADER&gt;0001209191-16-145281.hdr.sgml : 20161006
&lt;ACCEPTANCE-DATETIME&gt;20161006175047
ACCESSION NUMBER:       0001209191-16-145281
CONFORMED SUBMISSION TYPE:  4
PUBLIC DOCUMENT COUNT:      1
CONFORMED PERIOD OF REPORT: 20161006
FILED AS OF DATE:       20161006
DATE AS OF CHANGE:      20161006

ISSUER:     

    COMPANY DATA:   
        COMPANY CONFORMED NAME:         TEJON RANCH CO
        CENTRAL INDEX KEY:          0000096869
        STANDARD INDUSTRIAL CLASSIFICATION: REAL ESTATE [6500]
        IRS NUMBER:             770196136
        STATE OF INCORPORATION:         DE
        FISCAL YEAR END:            1231

    BUSINESS ADDRESS:   
        STREET 1:       4436 LEBEC ROAD
        STREET 2:       PO BOX 1000
        CITY:           LEBEC
        STATE:          CA
        ZIP:            93243
        BUSINESS PHONE:     6612483000

    MAIL ADDRESS:   
        STREET 1:       4436 LEBEC RD
        STREET 2:       PO BOX 1000
        CITY:           LEBEC
        STATE:          CA
        ZIP:            93243

REPORTING-OWNER:    

    OWNER DATA: 
        COMPANY CONFORMED NAME:         Bielli Gregory S.
        CENTRAL INDEX KEY:          0001597159

    FILING VALUES:
        FORM TYPE:      4
        SEC ACT:        1934 Act
        SEC FILE NUMBER:    001-07183
        FILM NUMBER:        161925684

    MAIL ADDRESS:   
        STREET 1:       P.O. BOX 1000
        CITY:           LEBEC
        STATE:          CA
        ZIP:            93243
&lt;/SEC-HEADER&gt;
&lt;DOCUMENT&gt;
&lt;TYPE&gt;4
&lt;SEQUENCE&gt;1
&lt;FILENAME&gt;doc4.xml
&lt;DESCRIPTION&gt;FORM 4 SUBMISSION
&lt;TEXT&gt;
&lt;XML&gt;
&lt;?xml version="1.0"?&gt;
&lt;ownershipDocument&gt;

    &lt;schemaVersion&gt;X0306&lt;/schemaVersion&gt;

    &lt;documentType&gt;4&lt;/documentType&gt;

    &lt;periodOfReport&gt;2016-10-06&lt;/periodOfReport&gt;

    &lt;notSubjectToSection16&gt;0&lt;/notSubjectToSection16&gt;

    &lt;issuer&gt;
        &lt;issuerCik&gt;0000096869&lt;/issuerCik&gt;
        &lt;issuerName&gt;TEJON RANCH CO&lt;/issuerName&gt;
        &lt;issuerTradingSymbol&gt;TRC&lt;/issuerTradingSymbol&gt;
    &lt;/issuer&gt;

    &lt;reportingOwner&gt;
        &lt;reportingOwnerId&gt;
            &lt;rptOwnerCik&gt;0001597159&lt;/rptOwnerCik&gt;
            &lt;rptOwnerName&gt;Bielli Gregory S.&lt;/rptOwnerName&gt;
        &lt;/reportingOwnerId&gt;
        &lt;reportingOwnerAddress&gt;
            &lt;rptOwnerStreet1&gt;P.O. BOX 1000&lt;/rptOwnerStreet1&gt;
            &lt;rptOwnerStreet2&gt;&lt;/rptOwnerStreet2&gt;
            &lt;rptOwnerCity&gt;TEJON RANCH&lt;/rptOwnerCity&gt;
            &lt;rptOwnerState&gt;CA&lt;/rptOwnerState&gt;
            &lt;rptOwnerZipCode&gt;93243&lt;/rptOwnerZipCode&gt;
            &lt;rptOwnerStateDescription&gt;&lt;/rptOwnerStateDescription&gt;
        &lt;/reportingOwnerAddress&gt;
        &lt;reportingOwnerRelationship&gt;
            &lt;isDirector&gt;1&lt;/isDirector&gt;
            &lt;isOfficer&gt;1&lt;/isOfficer&gt;
            &lt;isTenPercentOwner&gt;0&lt;/isTenPercentOwner&gt;
            &lt;isOther&gt;0&lt;/isOther&gt;
            &lt;officerTitle&gt;President/ CEO&lt;/officerTitle&gt;
        &lt;/reportingOwnerRelationship&gt;
    &lt;/reportingOwner&gt;

    &lt;nonDerivativeTable&gt;
        &lt;nonDerivativeTransaction&gt;
            &lt;securityTitle&gt;
                &lt;value&gt;Tejon Ranch Co. Common Stock&lt;/value&gt;
            &lt;/securityTitle&gt;
            &lt;transactionDate&gt;
                &lt;value&gt;2016-10-06&lt;/value&gt;
            &lt;/transactionDate&gt;
            &lt;deemedExecutionDate&gt;&lt;/deemedExecutionDate&gt;
            &lt;transactionCoding&gt;
                &lt;transactionFormType&gt;4&lt;/transactionFormType&gt;
                &lt;transactionCode&gt;A&lt;/transactionCode&gt;
                &lt;equitySwapInvolved&gt;0&lt;/equitySwapInvolved&gt;
            &lt;/transactionCoding&gt;
            &lt;transactionTimeliness&gt;
                &lt;value&gt;&lt;/value&gt;
            &lt;/transactionTimeliness&gt;
            &lt;transactionAmounts&gt;
                &lt;transactionShares&gt;
                    &lt;value&gt;28122&lt;/value&gt;
                    &lt;footnoteId id="F1"/&gt;
                &lt;/transactionShares&gt;
                &lt;transactionPricePerShare&gt;
                    &lt;value&gt;24.32&lt;/value&gt;
                &lt;/transactionPricePerShare&gt;
                &lt;transactionAcquiredDisposedCode&gt;
                    &lt;value&gt;A&lt;/value&gt;
                &lt;/transactionAcquiredDisposedCode&gt;
            &lt;/transactionAmounts&gt;
            &lt;postTransactionAmounts&gt;
                &lt;sharesOwnedFollowingTransaction&gt;
                    &lt;value&gt;55806&lt;/value&gt;
                    &lt;footnoteId id="F1"/&gt;
                &lt;/sharesOwnedFollowingTransaction&gt;
            &lt;/postTransactionAmounts&gt;
            &lt;ownershipNature&gt;
                &lt;directOrIndirectOwnership&gt;
                    &lt;value&gt;D&lt;/value&gt;
                &lt;/directOrIndirectOwnership&gt;
            &lt;/ownershipNature&gt;
        &lt;/nonDerivativeTransaction&gt;
        &lt;nonDerivativeTransaction&gt;
            &lt;securityTitle&gt;
                &lt;value&gt;Tejon Ranch Co. Common Stock&lt;/value&gt;
            &lt;/securityTitle&gt;
            &lt;transactionDate&gt;
                &lt;value&gt;2016-10-06&lt;/value&gt;
            &lt;/transactionDate&gt;
            &lt;deemedExecutionDate&gt;&lt;/deemedExecutionDate&gt;
            &lt;transactionCoding&gt;
                &lt;transactionFormType&gt;4&lt;/transactionFormType&gt;
                &lt;transactionCode&gt;F&lt;/transactionCode&gt;
                &lt;equitySwapInvolved&gt;0&lt;/equitySwapInvolved&gt;
            &lt;/transactionCoding&gt;
            &lt;transactionTimeliness&gt;
                &lt;value&gt;&lt;/value&gt;
            &lt;/transactionTimeliness&gt;
            &lt;transactionAmounts&gt;
                &lt;transactionShares&gt;
                    &lt;value&gt;12753&lt;/value&gt;
                    &lt;footnoteId id="F1"/&gt;
                    &lt;footnoteId id="F2"/&gt;
                &lt;/transactionShares&gt;
                &lt;transactionPricePerShare&gt;
                    &lt;value&gt;24.32&lt;/value&gt;
                &lt;/transactionPricePerShare&gt;
                &lt;transactionAcquiredDisposedCode&gt;
                    &lt;value&gt;D&lt;/value&gt;
                &lt;/transactionAcquiredDisposedCode&gt;
            &lt;/transactionAmounts&gt;
            &lt;postTransactionAmounts&gt;
                &lt;sharesOwnedFollowingTransaction&gt;
                    &lt;value&gt;43053&lt;/value&gt;
                    &lt;footnoteId id="F1"/&gt;
                &lt;/sharesOwnedFollowingTransaction&gt;
            &lt;/postTransactionAmounts&gt;
            &lt;ownershipNature&gt;
                &lt;directOrIndirectOwnership&gt;
                    &lt;value&gt;D&lt;/value&gt;
                &lt;/directOrIndirectOwnership&gt;
            &lt;/ownershipNature&gt;
        &lt;/nonDerivativeTransaction&gt;
    &lt;/nonDerivativeTable&gt;

    &lt;footnotes&gt;
        &lt;footnote id="F1"&gt;Shares are held in the Bielli Family Trust&lt;/footnote&gt;
        &lt;footnote id="F2"&gt;Shares used for taxes&lt;/footnote&gt;
    &lt;/footnotes&gt;

    &lt;remarks&gt;&lt;/remarks&gt;

    &lt;ownerSignature&gt;
        &lt;signatureName&gt;/s/ Gregory S. Bielli&lt;/signatureName&gt;
        &lt;signatureDate&gt;2016-10-06&lt;/signatureDate&gt;
    &lt;/ownerSignature&gt;
&lt;/ownershipDocument&gt;
&lt;/XML&gt;
&lt;/TEXT&gt;
&lt;/DOCUMENT&gt;
&lt;/SEC-DOCUMENT&gt;
</code></pre>

<p>If I wanted to extract something like <code>nonDerivativeTransaction</code></p>

<p>I would normally think to do something like <code>xpath('//nonDerivativeTransaction')</code>, but I cannot figure out the proper query string.</p>

<p>Like if I were using selenium and wrote:</p>

<p><code>driver.find_elements_by_xpath('//nonDerivativeTransaction')</code></p>

<p>I have tried things like:</p>

<pre><code>import urllib2
from lxml import etree
from lxml import html
response = urllib2.urlopen('ftp://ftp.sec.gov/edgar/data/96869/0001209191-16-145281.txt')
html_doc = response.read()
root = html.fromstring(html_doc)
tree = root.getroottree()
x=tree.xpath("nonderivativetable")
</code></pre>

<p>but with no luck.</p>

<p>How would I solve this problem?</p>