How to use try, except, else correctly in Python

Question

So I want to know which is the right way to write try except statements. I'm new to error handling in Python.

Option 1

try:
    itemCode = items["itemCode"]
    dbObject=db.GqlQuery("SELECT * FROM %s WHERE code=:1" % dbName,itemCode).get()
    dbObject.delete() 
except AttributeError:
    print "There's no item with that code"
except KeyError:
    print "Bad parameter name"
except:
    print "Unknow error" 

Option 2

try:
    itemCode = items["itemCode"]
except KeyError:
    print "Bad parameter name"
else:    
    dbObject=db.GqlQuery("SELECT * FROM %s WHERE code=:1" % dbName,itemCode).get()
    try:    
        dbObject.delete() 
    except AttributeError:
        print "There's no item with that code"
    except:
        print "Unknow error" 

Option 3 Any other better option you can think of.

Option 1, we see that I wrap all the code in a try block. Option 2, it uses nested blocks. It raises an exception on specific line statements.

If there's an error somewhere I will be glad to know about it.

Answer 1

From the zen of python, "flat is better than nested." I'd go with Option #1 style in general, though I'm a bit confused as to whether dbObject=db.GqlQuery("SELECT.... or dbObject.delete() raises an AttributeError. In any case though, you shouldn't have to call the dbObject.delete() more than once.