What is the most Pythonic way to test for match with first item of tuple in sequence of 2-tuples?
<p>Suppose you have a sequence of 2-tuples:</p>

<pre><code>seq_of_tups = (('a', 1), ('b', 2), ('c', 3))
</code></pre>

<p>and you want to test if <code>'a'</code> is the first item of any tuple in the sequence.</p>

<p>What is the most Pythonic way? </p>

<p>Convert to a dictionary and test for keys, which seems easy enough to understand? i.e.</p>

<pre><code>'a' in dict(seq_of_tups)
</code></pre>

<p>Use a cute zip trick which is is not particularly clear unless you know the trick? i.e.</p>

<pre><code>'a' in zip(*seq_of_tups)[0]
</code></pre>

<p>Or be really explicit with map? i.e.</p>

<pre><code>'a' in map(lambda tup: tup[0], seq_of_tups)
</code></pre>

<p>Or is there a better way than any of these choices? </p>
