title: use python list comprehension to update dictionary value
body: <p>I have a list of dictionaries and would like to update the value for key 'price' with 0 if key price value is equal to '' </p>
  
  <pre><code>data=[a['price']=0 for a in data if a['price']=='']
  </code></pre>
  
  <p>Is it possible to do something like that? I have tried also with</p>
  
  <pre><code>a.update({'price':0})
  </code></pre>
  
  <p>but did not work as well...</p>