Google App Engine Python adding

class Config(db.Model):

    Latest = db.IntegerProperty()

    class New(webapp.RequestHandler): 
        def get(self): 
            config = Config()
            Last = Config.Latest
            t = Last + 1

returns

t = LastUUID + ADDNUM
TypeError: unsupported operand type(s) for +: 'Intege开发者_如何转开发rProperty' and 'Int'

What im trying to do is get the int from the datastore and app 1 to it. Then reassign the int in the datastore. I have no clue why it is throwing these errors. I even tried t = int(Last +1). UPDATE: This is what i needed and solved my problem. http://code.google.com/appengine/articles/sharding_counters.html

The changes you need are more than tweaking a single line.

You need some sort of initialisation function which will create a Config() instance, assign Latest an initial value (like 1 or 0) and store it in the datastore.

Then your RequestHandler needs to execute a query to retrieve the relevant Config instance. Finally, update Latest, and save the instance into the datastore again.

This has nothing to do with Google App Engine or Django. In the following code:

class X(object):
    @property
    def y(self):
        return 5

x = X()
print X.y + 5

... you get the same error. X.y refers to the unbound property on the class object. x.y refers to the bound property, and indeed in the above example print x.y + 5 prints "10".

Change the line to Last = config.Latest and it should work. And I strongly recommend you take up the recommendations in PEP 8, particularly under "Prescriptive: Naming Conventions". Generally speaking, in Python classes should use CapWords, while functions and variables should use lowercase_with_underscores.

The syntax you're looking for is

t = int(Last) +1

However, I'm not sure that's what you want to do. I don't know django or whatever framework this is so it's hard to say. But in python, types must be compatible for you to add them.

http://code.google.com/appengine/articles/sharding_counters.html

This is a basic conter that can be updated multiple times a second. Works perfect