title: What is the best way to fillter null from a list in dart language
body: <p>Looking for a dart equivalent of python filter</p>
  
  <pre><code>a = ['', None,4]
  [print(e) for e in filter(None,a)]
  </code></pre>
  
  <p>My code is too ugly:</p>
  
  <pre><code>List a = [null,2,null];
  List b=new List();
  for(var e in a){if(e==null) b.add(e);}
  for(var e in b){a.remove(e);}
  print(a);
  </code></pre>