title: scrapy get the entire text including children
body: <p>I have a series of <code>&lt;p&gt;</code> elements inside a document I'm scraping with scrapy.<br>
  some of the are: 
  <code>&lt;p&gt;&lt;span&gt;bla bla bla&lt;/span&gt;&lt;/p&gt;</code>
  or
  <code>&lt;p&gt;&lt;span&gt;&lt;span&gt;bla bla bla&lt;/span&gt;&lt;span&gt;second bla bla&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;</code></p>
  
  <p>I want to extract all the text with the children (assume I already have the selector of the <code>&lt;p</code>)<br>
  (second example: to have a string <code>bla bla bla second bla bla</code>)</p>