reason for using three open-close quotes when using re.verbose in python
<p>I'm just curious as to why most examples I've seen that make use of re.verbose when using regular expressions, use '''?</p>

<p>An example I found is shown below</p>

<pre><code>address = re.compile(
    '''              #THIS
    [\w\d.+-]+       # username
    @
    ([\w\d.]+\.)+    # domain name prefix
    (com|org|edu)    # we should support more top-level domains
    ''',             #AND  THIS  
    re.UNICODE | re.VERBOSE)
</code></pre>
