Python Running Sum in List
<p>Given the following list:</p>

<pre><code>a=[1,2,3]
</code></pre>

<p>I'd like to generate a new list where each number is the sum of it and the values before it, like this:</p>

<pre><code>result = [1,3,6]
</code></pre>

<p>Logic: </p>

<p>1 has no preceding value, so it stays the same.</p>

<p>3 is from the first value (1) added to the value of the second number in the list (2)</p>

<p>6 is from the sum of 1 and 2 from the first two elements, plus the third value of 3.</p>

<p>Thanks in advance!</p>