title: Variable in Flask static files routing [url_for('static', filename='')]
body: <p>I'm making a simple music app.
  I want to allow users upload their audio files and I have a page where I'm planning to show all songs.
  I've created a template, and the structure looks like:</p>
  
  <pre><code>{% for song in songs %}
      &lt;div class="chart-item"&gt;
          &lt;div class="chart-position col-md-1"&gt;
              &lt;h3&gt;#u&lt;/h3&gt;
          &lt;/div&gt; &lt;!-- chart-position --&gt;
          &lt;div class="band-logo col-md-2"&gt;
              &lt;img src="{{ url_for('static', filename='uploads/users/{{ song['artistName'] }}/{{ song['pathToCover'] }}')}}"&gt;
          &lt;/div&gt; &lt;!-- band-logo --&gt;
          &lt;div class="band-name-and-autio col-md-9"&gt;
              &lt;div class="band-name"&gt;{{ song['artistName'] }} - {{ song['songName'] }}&lt;/div&gt; &lt;!-- band-name --&gt;
              &lt;div class="audio"&gt;
                  &lt;audio&gt;
  
                  &lt;/audio&gt;
              &lt;/div&gt; &lt;!-- audio --&gt;
          &lt;/div&gt; &lt;!-- band-name-and-autio --&gt;
          &lt;div class="clearfix"&gt;&lt;/div&gt;
      &lt;/div&gt; &lt;!-- chart-item --&gt;
  {% endfor %}
  </code></pre>
  
  <p>Here I want to make a dynamical path to cover image and a record, but I do not know to correctly write the path to the file here:</p>
  
  <pre><code>&lt;img src="{{ url_for('static', filename='uploads/users/{{ song['artistName'] }}/{{ song['pathToCover'] }}')}}"&gt;
  </code></pre>
  
  <p>Please, explain how to do it. I've tried to find the solution on flask web page, but for now I have no any result.</p>