Primitives, composition, abstraction, and patterns, Python Programming

 

Primitives, Composition, Abstraction, and Patterns

 

We will  start  by thinking about  how  the  PCAP  framework applies to computer programs, in general. We may do that by taking in table 3.1, exploring the PCAP concepts in data, functions, and objects.

 

Data

 

The primitive data  items in most programming languages are things  like integer variables, ?oating point values, and  strings. We can use those into data  structures  such as lists, dictionaries, arrays and records. Creating  a data  structure  allows  us,  at the  most  simple  level,  to think  of a type  of primitive data  elements as if it were  one thing,  freeing  us from information.   Sometimes, we just think  of a section  of data,  not  in type  of its relaying representation, but  in terms  of what  it shows.  So, we may think  of a set of functions, or a family  tree, without thinking whether it is an array or a list in its basic representation. Abstract data  types  gives a way  of abstracting away  from representational details  and allowing us to focus on what  the data  really means.

 

 

Procedures

 

The primitive procedures of a language are things  like built-in  numeric operations and  basic list application. We may combine these  using  the facilities of the language, such as if and  while, or by using  procedure composition (f(g(x))).  If we try  to abstract away  from  the details  of how a particular calculation is done,  we can describe  a new  function; de?ning a function allows  us to use it for computational programs without thinking about  the information  of how  those  computational jobs get completed.   You can think  of this  process  as essentially creating a new  primitive, which  we may then  use  while  ignoring the information  of how  it is created.  One  way  to save common patterns of abstraction in method is to abstract over functions themselves, with higher-order methods.

 

Objects

 

Object-oriented programming provides a number of methods of abstraction and  pattern capture in both  data  and  function. At the most  basic level, objects can be used  as files, combining with primitive data  component. More usually, they give strategies for jointly abstracting a data  representation and the procedures that work  on it. The features of polymorphism and inheritance are particularly important.

 

Procedures

Data

Primitives

Means of combination

Means of abstraction

Means of capturing patterns

+, *, ==

if, while, f(g(x))

def

higher-order procedures

numbers, strings

lists, dictionaries, objects

ADTS, classes

Generic functions, inheritance




 

 

 

 

 

 

Table 3.1          Primitives, combination, abstraction, patterns framework for computer programs

 

Posted Date: 8/11/2012 1:30:02 AM | Location : United States







Related Discussions:- Primitives, composition, abstraction, and patterns, Assignment Help, Ask Question on Primitives, composition, abstraction, and patterns, Get Answer, Expert's Help, Primitives, composition, abstraction, and patterns Discussions

Write discussion on Primitives, composition, abstraction, and patterns
Your posts are moderated
Related Questions
Procedures in Firrst-class objects In Python, unlike  many  other  languages, methods are behave in much  the same way as num­ bers:  they  can be stored as values  of variabl

Python programs Every  general-purpose computer has a various detailed design, which  defines  that  the way  its program requires  to be specified is different. The "machine

Booleans   Before we talk about  conditionals, we require  to clarify the Boolean  data  type.  It has two values False and True. Typical statement that have Boolean values

The goal of this exercise is to write a \business phrase" generator, which each time it is called produces lines of business speak, such as: It's time that we became uber-effici

Print vs Return Here are two different method declarations: def f1(x): print x + 1 def f2(x): return x + 1 What happens when  we call them? >>> f1(3) 4 >>

Python  Style Software  engineering courses  often  provide very  rigid  guidelines on the style of programming, generally the appropriate value of indentation, or what  to us

Procedures in python Procedures are computer program creates that let us capture common patterns of computation by: Grouping together sequences of statements

#ques Write the pseudocode (use a word processor please) and the Python 3.0 program for the following problem. A monkey is being fed some food. Read in the starting weight in lbs:o

Write a program that requests a password after the author/program information is displayed. Make the password "hello". The program should then ask the user for their name: if the n

Normalize a vector Let's imagine we want  to normalize a vector  of three  variables;  that  is to compute a new  vector  of three values,  such that its size  is 1. Here is o