title: Delete element from nested hash in Ruby
body: <p>I have a two dimensional hashes in Ruby.</p>
  
  <pre><code>h = { "a" =&gt; {"v1" =&gt; 0, "v2" =&gt; 1}, "c" =&gt; {"v1" =&gt; 2, "v2" =&gt; 3} }
  </code></pre>
  
  <p>I would like to delete those elements from the hash, where value 1 (<code>v1</code>) is 0, for example, so my result would be:</p>
  
  <pre><code>{ "c" =&gt; {"v1" =&gt; 2, "v2" =&gt; 3} }
  </code></pre>
  
  <p>I wanted to achieve this by iterating trough the hash with <code>delete_if</code>, but I'm not sure how to handle the nested parts with it.</p>