title: Python, dictionary sum value
body: <p>I have a dictionary obtained as following: </p>
  
  <pre><code>test= {'Test': [sum(t) for t in zip(*data.values())],}
  </code></pre>
  
  <p>And suppose that the test values as the following: </p>
  
  <pre><code>test={ 'Test': [ t1, t2, t3, t4, t5 ] }
  </code></pre>
  
  <p>I want to obtain the following result: </p>
  
  <pre><code>results={ 'Test': [ r1=t1 , r2=r1+t2 , r3=r2+t3 , r4=r3+t4 , r5=r4+t5 ] }
  </code></pre>
  
  <p>And finally, if the results values are negative, set equal to zero. </p>
  
  <p>How could I get it?</p>