Given a list of Tuples, return a new list of the first values of the tuples
<p>I have a list of tuples and I want a new list consisting of the first values of the tuples.</p>

<p>I.e. if the list is:</p>

<p>[(1,5),(4,10),(100,3),(4,8)]</p>

<p>I want to create the following list:</p>

<p>[1,4,100,4]</p>

<p>The following code works:</p>

<pre><code>a = [(1,5),(4,10),(100,3),(4,8)]
l = []
for i in range(len(a)):
    l.append(a[i][0])
</code></pre>

<p>But it seems there should be a better way, for example:</p>

<pre><code>l = itertools.chain(for i in range(len(a)) a[i][0]) #This won't work
</code></pre>
