[Tutor] Self, Scopes and my unbelievable muddleheadedness.

[John Fouhy]

On 26/10/06, doug shawhan <doug.shawhan at gmail.com> wrote:
>  class Create:
>      def freshDB(self, DBPATH, Fields):
>           # ...
>      def comparisonTable(self, DBPATH, Fields, columns, mode):
>           # ...
>  Now when I run freshDB from the other script:
>
>  Fields = {"Common":"Inventory_Number, Stock_Number, Location, Year, Make,
> Model, Part_Type, Mileage, Description, Interchange_Data, Condition, Price",
>      "EvilBay":"EvilBay_Title, EvilBay_Description",
>      "HappyBase":"HappyBase_Description,
> HappyBase_Long_Description"}
>
>  d = DBMod
>
>  d.Create().freshDB(DBPATH, Fields)
>
>  d.Create().comparisonTable(DBPATH, Fields, columns, "new")

What is the purpose of your Create class?  It seems to me that you are
not actually doing anything object-oriented here.  So maybe you're
confused about 'self' because you've got no object orientation?

I think you've got a couple of ways forward.  You could abandon your
class, and just put the functions directly into a module; ie:

###### creategadfly.py #######

def freshDB(dbpath, fields):
   # etc

def comparisonTable(dbpath, fields, columns, mode):
   # etc

######

and then, in your code, you would do:

import creategadfly
creategadfly.freshDB(DBPATH, Fields)
creategadfly.comparisonTable(DBPATH, Fields, columns, "new")

Alternatively, you could restructure your code to make it OO.
Something like this:

######

class GadflyConnection(object):
   def __init__(self, dbpath, dbname, fields):
       self.createDB(dbpath, dbname, fields)

   def createDB(self, dbpath, dbname, fields):
       self.db = gadfly.gadfly()
       self.db.startup(dbname, dbpath)
       # etc

   def comparisonTable(self, mode):
       if mode == 'new':
           # insert code to create 'query'
           cursor = self.db.cursor()
           cursor.execute(query)
           cursor.close()

Maybe you would want a call to self.comparisonTable inside __init__?

Then to use:

gadflyDB = GadflyConnection(...)

I'm not sure what you want to do with your database, so I can't really
give you a bigger use example.  But do you see what is going on?  In
createDB(), you create a new gadfly connection, and then assign it to
'self.db'.  Then, in comparisonTable, you can reference self.db to
access that connection.

Hope this helps.

--
John.