finer exception handling

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Greetings all,

I need to handle an exception test case to distinguish the following results
out of a query:

1. the postgres server is down
2. the login password is wrong
3. the database does not exist

I have played around catching the psycopg2 exceptions as documented here:

   http://initd.org/psycopg/docs/module.html#exceptions

I can't find a way to classify the error cases mentioned above. The pgerror
and pgcode exception variables arrive as None objects to me whenever I catch
any of the exceptions. I can't rely on the error messages as my application
is multilingual. I am using Ubuntu 9.10 karmic. Code snippet follows...

try:
   connection = psycopg2.connect("dbname='%s' user='postgres' password='%s'
host='localhost'" % (dbname,
postgres_password));
   cur = connection.cursor()
   cur.execute ('select something')
   r = cur.fetchone()
except psycopg2.InterfaceError:
   print "interface"
   return False
except psycopg2.DatabaseError:
   print "database"
   return False
except psycopg2.OperationalError:
   print "operational"
   return False

Guidance much appreciated
Albert

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Greetings all,<br><br>I need to handle an exception test case to distinguis=
h the following results out of a query:<br><br>1. the postgres server is do=
wn<br>2. the login password is wrong<br>
3. the database does not exist<br><br>I have played around catching the psy=
copg2 exceptions as documented here:<br><br>=A0=A0 <a href=3D"http://initd.=
org/psycopg/docs/module.html#exceptions">http://initd.org/psycopg/docs/modu=
le.html#exceptions</a><br>
<br>I can&#39;t find a way to classify the error cases mentioned above. The=
 pgerror and pgcode exception variables arrive as None objects to me whenev=
er I catch any of the exceptions. I can&#39;t rely on the error messages as=
 my application is multilingual. I am using Ubuntu 9.10 karmic. Code snippe=
t follows...<br>
<br>try:<br>=A0=A0 connection =3D psycopg2.connect(&quot;dbname=3D&#39;%s&#=
39; user=3D&#39;postgres&#39; password=3D&#39;%s&#39; host=3D&#39;localhost=
&#39;&quot; % (dbname, postgres_password));=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=
=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=
=A0=A0=A0=A0=A0=A0=A0 <br>
=A0=A0 cur =3D connection.cursor()<br>=A0=A0 cur.execute (&#39;select somet=
hing&#39;)<br>=A0=A0 r =3D cur.fetchone()<br>except psycopg2.InterfaceError=
:<br>=A0=A0 print &quot;interface&quot;<br>=A0=A0 return False<br>except ps=
ycopg2.DatabaseError:<br>
=A0=A0 print &quot;database&quot;<br>=A0=A0 return False<br>except psycopg2=
.OperationalError:<br>=A0=A0 print &quot;operational&quot;<br>=A0=A0 return=
 False<br><br>Guidance much appreciated<br>Albert<br><br>

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