title: python replace content of url between <br/> and <br/>
body: <p>There's a string like this:</p>
  
  <pre><code>&lt;p&gt;Millions of people watch TV.&lt;/p&gt;&lt;br/&gt;https://sites.google.com/aaa-net.bb.cc/be-do-have/%E3%83%9B%E3%83%BC%E3%83%A0&lt;br/&gt;&lt;p&gt;Good boy!&lt;/p&gt;&lt;br/&gt;
  </code></pre>
  
  <p>I want to delete the content:</p>
  
  <pre><code>https://sites.google.com/aaa-net.bb.cc/be-do-have/%E3%83%9B%E3%83%BC%E3%83%A0
  </code></pre>
  
  <p>Just keep:</p>
  
  <pre><code>&lt;p&gt;Millions of people watch TV.&lt;/p&gt;&lt;br/&gt;&lt;br/&gt;&lt;p&gt;Good boy!&lt;/p&gt;&lt;br/&gt;
  </code></pre>
  
  <p>My code:</p>
  
  <pre><code>mystring = '&lt;p&gt;Millions of people watch TV.&lt;/p&gt;&lt;br/&gt;https://sites.google.com/aaa-net.bb.cc/be-do-have/%E3%83%9B%E3%83%BC%E3%83%A0&lt;br/&gt;&lt;p&gt;Good boy!&lt;/p&gt;&lt;br/&gt;'
  </code></pre>
  
  <p>How to do it?</p>