vgg_rules

This is an experimental project for implementing rule engine(business_rule) in Python.

The project is a console application based on Django 1.6, implementing promotion calculations in business system:

All goods are priced individually. Some items are also multi-priced based on quantity bought. Buy n of them, and they’ll cost you y cents.
Pricing changes frequently
Items could have multiple rules

The rule script in json format is saved in database and will be read and implemented to all the items ordered.

Rule Script Examples:

The "name" in "condtions" is defined in python class OrderDetailVariables. The "name" in "action" is defined in python class OrderDetailActions.

####1. Buy 3 oranges in a group at price $1.80 each(10% off).

{ "conditions": { "all": [
      { "name": "product_code",
        "operator": "equal_to",
        "value": "ORANGE"
      },
      { "name": "product_amount",
        "operator": "greater_than_or_equal_to",
        "value": 3
      }
  ]},
  "actions": [
      { "name": "buy_group_and_cheaper",
        "params": {"group_count": 3,  "sale_price": 180}
      }
  ]
}

####2. Buy 5 apple, get 2 free

{ "conditions": { "all": [
      { "name": "product_code",
        "operator": "equal_to",
        "value": "APPLE"
      },
      { "name": "product_amount",
        "operator": "greater_than_or_equal_to",
        "value": 5
      }
  ]},
  "actions": [
      { "name": "buy_and_get_cheaper",
        "params": {"buy_count": 5,  "cheaper_count": 2, "sale_percentage": 0}
      }
  ]
}

Command Usage

1. Create a new order

This command will create a new order.

$ python manage.py createorder

2. Purchase Items

This command will add item to specified order. If the same item has been added, the amount will add up.

$ python manage.py additem <order_number> <product_code> <amount>

3. List orders

List all the orders.

$ python manage.py listorders

A sample order list:


Order Count: 2
Order Num: 6QIE1405909818 | Status: Checkout(1) | Date: 2014-07-21 02:30:18+00:00
Order Num: WIY51405918562 | Status: New(0) | Date: 2014-07-21 04:56:02+00:00

4. Checkout Order

Check out order, change the order status, and implement all the available promotion rules to purchased items.

$ python manage.py checkout <ordre_number>

5. Print the order invoice

$ python manage.py invoice <ordre_number>

A sample invoice:


Order Number: WIY51405918562
REGLR PRICE  3800.00
PRMTN PRICE  3120.00
================= ITEMS ==============
CODE:APPLE     NAME:red apple
REGLR PRICE  2000.00
PRMTN PRICE  1500.00
Promotion APPLE2_1
Buy 5 apple, get 2 free
-----------------------------
CODE:ORANGE     NAME:big orange
REGLR PRICE  1800.00
PRMTN PRICE  1620.00
Promotion ORANGE_3
Buy 3 oranges in a group at price $1.80 each(10% off)
-----------------------------