title: Using a 'Where' filter in Jekyll to only return items that are not blank
body: <p>I have a CSV data file that contains a list of projects. I would like to assign variables to filtered segments of the data - then loop through them. </p>
  
  <p>Here I have tried to filter all projects to show only the projects that have been assigned a value in the <code>global_priority</code> field. If the project has no value I do not what it in the list. </p>
  
  <p>I have tried using <code>where_exp</code>, but it returns everything. What is the best way to approach this? Is it possible to achieve this without using an <code>if</code> statement?</p>
  
  <p><strong>projects.csv</strong> </p>
  
  <pre><code>name,global_priority,region,region_priority
  Project A,1,Global,
  Project B,,Spain,1
  Project C,2,UK,1
  </code></pre>
  
  <p><strong>The loop</strong></p>
  
  <pre><code>{% assign projects = site.data.projects %}
  {% assign global_p = projects | where_exp: "item.global_priority", "item.global_priority != blank" %}
  
    {% for p in global_p %}
      &lt;ul&gt;
        &lt;li&gt;{{ p.global_priority }}&lt;/li&gt;
        &lt;li&gt;{{ p.region }}&lt;/li&gt;
        &lt;li&gt;{{ p.name }}&lt;/li&gt;
      &lt;/ul&gt;
    {% endfor %}
  </code></pre>