from xml.etree.ElementTree import fromstring

xdoc='''<?xml version="1.0" encoding="UTF-8"?>
<trajectorys xmlns="http://www.witsml.org/schemas/1series" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="1.4.1.1">
  <trajectory uidWell="b04e88c7-72c1-443e-aecc-8ea3c6" uidWellbore="6ed5bb6b-f6e6-465b-9879-d87220f8" uid="T-3610902-1" xmlns="http://www.witsml.org/schemas/1series">
    <trajectoryStation uid="S-0">
      <dTimStn>2015-11-14T19:13:08.000Z</dTimStn>
      <typeTrajStation>tie in point</typeTrajStation>
      <md uom="m">0</md>
      <tvd uom="m">0</tvd>
      <incl uom="dega">0</incl>
      <azi uom="dega">0</azi>
      <dispNs uom="m">-12.52</dispNs>
      <dispEw uom="m">23.28</dispEw>
      <vertSect uom="m">-15.2637961330213</vertSect>
      <dls uom="dega/m">0</dls>
      <gravTotalUncert uom="m/s2">0.0181423</gravTotalUncert>
      <dipAngleUncert uom="dega">0.45</dipAngleUncert>
      <magTotalUncert uom="nT">300</magTotalUncert>
      <gravAccelCorUsed>false</gravAccelCorUsed>
      <magXAxialCorUsed>false</magXAxialCorUsed>
      <sagCorUsed>true</sagCorUsed>
      <magDrlstrCorUsed>false</magDrlstrCorUsed>
      <gravTotalFieldReference uom="m/s2">9.82253599999999</gravTotalFieldReference>
      <magTotalFieldReference uom="nT">51091.2</magTotalFieldReference>
      <magDipAngleReference uom="dega">73.28</magDipAngleReference>
      <statusTrajStation>position</statusTrajStation>
      <corUsed>
        <gravAxialAccelCor uom="m/s2">0</gravAxialAccelCor>
        <gravTran1AccelCor uom="m/s2">0</gravTran1AccelCor>
        <gravTran2AccelCor uom="m/s2">0</gravTran2AccelCor>
        <magAxialDrlstrCor uom="nT">0</magAxialDrlstrCor>
        <magTran1DrlstrCor uom="nT">0</magTran1DrlstrCor>
        <magTran2DrlstrCor uom="nT">0</magTran2DrlstrCor>
        <sagIncCor uom="dega">0</sagIncCor>
        <sagAziCor uom="dega">0</sagAziCor>
        <stnGridCorUsed uom="dega">0</stnGridCorUsed>
      </corUsed>
      <commonData>
        <dTimCreation>2016-04-04T23:26:07.485Z</dTimCreation>
        <dTimLastChange>2016-04-04T23:26:07.485Z</dTimLastChange>
      </commonData>
    </trajectoryStation>
  </trajectory>
</trajectorys>
'''

print([x.text for x in fromstring(xdoc).findall(".//md") if x.text])