an or a European swallow?
&gt;&gt;&gt; int(speed)
ValueError: invalid literal for int()
</font></pre><font color="black">We will see how to handle this kind of error later.</font><br />
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<h2><font color="black"><a name="htoc27">2.11</a>&nbsp;&nbsp;Comments</font></h2>
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<font color="black">As programs get bigger and more complicated, they get more difficult
to read. Formal languages are dense,