How to access a database initialized in a class from another class in python?
Question: How would I go about implementing the MainPage class?

    
    
    import cgi
    import os
    import logging
    
    from google.appengine.api import users
    from google.appengine.ext import webapp
    from google.appengine.ext.webapp.util import run_wsgi_app
    from google.appengine.ext import db
    
    class Greeting(db.Model):  #setting up database
      a = db.StringProperty(multiline=True)
      b = db.StringProperty(multiline=True)
      c = db.StringProperty(multiline=True)
      d = db.StringProperty(multiline=True)
    
    class MainPage(webapp.RequestHandler):
      def get(self):
    ##I want to access the content of the database here which is defined in Downloader class. 
    ##For example let the value of greeting.a be assigned to alpha variable.   
    
    
    #Entering data to the database
    class Downloader(webapp.RequestHandler):
        def get(self):
            greeting=Greeting()
            greeting.a=self.request.GET.get('a')
            greeting.b=self.request.GET.get('b')
            greeting.c=self.request.GET.get('c')
            greeting.d=self.request.GET.get('d')
            greeting.put()
    


Answer: You could pass a Downloader object to MainPage on initialization:

    
    
    class MainPage(webapp.RequestHandler):
        def __init__(self, downloader):
            self.downloader = downloader
    
        def get(self):
            self.downloader.get()
    

