Creating an enum in Python prior to Python 3.4 was accomplished as follows:

def enum(**enums)::
      return type('Enum',(),enums)

then use as:

Animals=enum(Dog=1,Cat=2)

and accessed as:

Animals.Dog

The new version can be created as follows:

from enum import Enum

class Animal(Enum):
    Dog=1
    Cat=2

Static variables in Python are created as part of the class declaration.  By contrast, instance variables are created as part of a regular method and not a classmethod or staticmethod.

class A:
  i=3  # static variable
	
  def dosomethingregularmethod(self):
       self.k=4   # instance variable
	
# to access static variables


A.i

A business rule is the basic unit of rule processing in a Business Rule Management System (BRMS) and, as such, requires a fundamental understanding. Rules consist of a set of actions and a set of conditions whereby actions are the consequences of each condition statement being satisfied or true. With rare exception, conditions test the property values of objects taken from an object model which itself is gleaned from a Data Dictionary and UML diagrams. See my article on Data Dictionaries for a better understanding on this subject matter.

A simple rule takes the form:

if condition(s)

then actions.

An alternative form includes an else statement where alternate actions are executed in the event that the conditions in the if statement are not satisfied:

if condition(s)

then actions

else alternate_actions

It is not considered a best prectice to write rules via nested if-then-else statements as they tend to be difficult to understand, hard to maintain and even harder to extend as the depth of these statements increases; in other words, adding if statements within a then clause makes it especially hard to determine which if statement was executed when looking at a bucket of rules. Moreoever, how can we determine whether the if or the else statement was satisfied without having to read the rule itself. Rules such as these are often organized into simple rule statements and provided with a name so that when reviewing rule execution logs one can determine which rule fired and not worry about whether the if or else statement was satisfied. Another limitation of this type of rule processing is that it does not take full advantage of rule inferencing and may have a negative performance impact on the Rete engine execution. Take a class with HSG and find out why.

Rule Conditions

One of the most significant developments of mankind has been the art of writing. The earliest type of writing was in the form of graffiti and paintings on rocks and walls of caves. The first people who engaged in writing are reported to have been Sumerians and the Egyptians around 3500-3200 BC.[i] Early writing of this type was in the form of cuneiform and hieroglyphics. After that, writing emerged in different styles and form per the different societies and differences in expression.

Words are magical. They have preserved records of civilizations. They express desires and dreams and thoughts. But why write at all? What was or is the motive for writing? People write for different reasons. Some write because they have something to say; something to share with others, to inform. Others write to share their feelings.

George Orwell claimed there are four main reasons why people write as depicted below:

·         Sheer Egoism: According to this concept, people write because they want to be talked about; they want to reveal their cleverness. People who are motivated by sheer egoism desire to be counted among the top crust of humanity such as scientists, artists, politicians, lawyers and successful businessmen who are always putting their thoughts in print.