title: lxml - XML Document with multiple NameSpaces
body: <p>is it possible to construct a XML as this one using lxml?</p>
  
  <pre><code>&lt;soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ns0="http://xmlns.CLT.com/consume/ENTBUS" xmlns:ns1="http://xmlns.CLT.com/Core/ENTBUS" xmlns:ns2="http://xmlns.CLT.com/output/EBO"&gt;
     &lt;soapenv:Header/&gt;
     &lt;soapenv:Body&gt;
        &lt;ns0:ConsumptionRequestENTBUS&gt;
           &lt;ns1:ENTBUSHeader&gt;
              &lt;ns1:ENTBUSID&gt;1&lt;/ns1:ENTBUSID&gt;
           &lt;/ns1:ENTBUSHeader&gt;
           &lt;ns0:Zone&gt;
              &lt;ns2:Consumption&gt;
                 &lt;ns2:BusCode&gt;1&lt;/ns2:BusCode&gt;
              &lt;/ns2:Consumption&gt;
           &lt;/ns0:Zone&gt;
        &lt;/ns0:ConsumptionRequestENTBUS&gt;
     &lt;/soapenv:Body&gt;
  &lt;/soapenv:Envelope&gt;
  </code></pre>
  
  <p>I tried building the root element as below but it fails. And almost every element needs to be namespace referenced.</p>
  
  <pre><code>&gt;&gt;&gt; from lxml import etree
  &gt;&gt;&gt; root = etree.Element("soapenv:Envelope")
  Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in &lt;module&gt;
    File "lxml.etree.pyx", line 2811, in lxml.etree.Element (src\lxml\lxml.etree.c:65389)
    File "apihelpers.pxi", line 103, in lxml.etree._makeElement (src\lxml\lxml.etree.c:13898)
    File "apihelpers.pxi", line 1575, in lxml.etree._tagValidOrRaise (src\lxml\lxml.etree.c:27955)
  ValueError: Invalid tag name u'soapenv:Envelope'
  </code></pre>
  
  <p>Thanks</p>