Pythonize if/else
<p>My mind is probably feeling Friday afternoon and I cannot see a way to pytonize the code below:</p>

<pre><code>filepath = None
if 'HALLO' in os.environ:
    filepath = os.environ['HALLO']
elif os.path.isfile( os.path.join(os.environ['HOME'], 'host.hallo') ):
    filepath = os.path.join(os.environ['HOME'], 'host.hallo')
elif os.path.isfile('/etc/app/host.hallo'):
    filepath = '/etc/app/host.hallo'
if filepath:
    print 'HALLO found in "%s"' % filepath
    ## do something
else:
    print 'HALLO not found!'
    ## do something else
</code></pre>

<p>Any idea on how to do it? Thanks!</p>

<p>ps: the code above is just an example, it can have a syntax error since I have written it directly here.</p>
