text: import os
  from flask import url_for
  from sqlalchemy import create_engine
  
  
  # import psycopg2
  # conn_string = "host='localhost' dbname='my_database' user='postgres' password='secret'"
  # conn = psycopg2.connect(conn_string)
  
  ZPARSER_URI = 'parse'
  
  # production environment
  # Database initialization
  if os.environ.get('DATABASE_URL'):
      # ZSERVER_URL = "http://z-grand-py.herokuapp.com"
  
      SQLALCHEMY_DATABASE_URI = os.environ['DATABASE_URL']
  
      GMAPS_KEY = os.environ['GMAPS_KEY']
      FONTAWESOME_ID = os.environ['FONTAWESOME_ID']
  
  
  # dev environment
  else:
      import param
  
      basedir = os.path.abspath(os.path.dirname(__file__))
      SQLALCHEMY_DATABASE_URI = 'sqlite:///' + os.path.join(basedir, 'app.db')
  
      SECRET_KEY = param.SECRET_KEY
  
      GMAPS_KEY = param.GMAPS_KEY
      FB_APP_ID = param.FB_APP_ID
      FONTAWESOME_ID = param.FONTAWESOME_ID
  
  # default
  # engine = create_engine('postgresql://scott:tiger@localhost/mydatabase')
  # psycopg2 explicit default version
  # engine = create_engine('postgresql+psycopg2://postgres:NoP@stGre23@localhost/lab_fb.db')
  # pg8000
  # engine = create_engine('postgresql+pg8000://scott:tiger@localhost/mydatabase')
  