title: Use lxml find element to parse Arxiv XML from API
body: <p>I'm fetching xml from Arxiv and I want to parse all Arxiv entries after reading it using <code>lxml</code> library. Here is my code to grab XML file of 100 of articles.</p>
  
  <pre><code>import urllib
  from lxml import etree
  
  start_index = 0
  results_per_iteration = 100
  base_url = 'http://export.arxiv.org/api/query?'
  search_query = 'cat:cs.CV+OR+cat:cs.LG+OR+cat:cs.CL+OR+cat:cs.NE+OR+cat:stat.ML'
  query = 'search_query=%s&amp;sortBy=lastUpdatedDate&amp;start=%i&amp;max_results=%i'\
      % (search_query, start_index, start_index + results_per_iteration)
  
  response = urllib.request.urlopen(base_url + query).read() # python 3.x
  # response = urllib.urlopen(base_url + query).read() # python 2.x
  tree = etree.fromstring(response)
  </code></pre>
  
  <p>Now, I have to do as following to find all entries from the xml.</p>
  
  <pre><code>e_ = tree.findall('{http://www.w3.org/2005/Atom}entry')
  </code></pre>
  
  <p>And in order to find <code>id</code>, I have to do the following</p>
  
  <pre><code>print(e_.find('{http://www.w3.org/2005/Atom}id').text)
  </code></pre>
  
  <p><strong>Question</strong> is I want to know if there is a way to parse this XML where we don't have to provide <code>{http://www.w3.org/2005/Atom}</code> when finding elements i.e. <code>tree.findall('entry')</code> or <code>lxml</code> script that has some functionality that works similar to <a href="https://github.com/kurtmckee/feedparser" rel="nofollow">feedparser</a>.</p>