Python Introduction, History, Philosophy And Features

Python is a high-level, multi-paradigm programming language developed by a Dutch programmer Guido van Rossum and is first released in 1991. The language is so easy to understand that a person either having or not having a basic knowledge of computer programming can get started with python as first programming language. Easy as ABC What do the alphabet [ [ ...]

Calculations by Machine

People have been calculating things for thousands of years and have always had mechanical aids to help. When someone programs a computer, they are really communicating with it. It is an imperative and precise communication. Imperative, because the computer has no choice; it is being told what to do and will do exactly that. Precise, [ [ ...]

How Computers Work and Why We Made Them

The reason people use computers is different depending on the point in his­tory in which one looks, but the military always seems to be involved. There have been many calculating devices built and used throughout history, but the first one that would have been programmable was designed by Charles Babbage. The military, as well as [ [ ...]

Computer Systems Are Built in Layers

Entering a program as binary numbers using switches is a very tedious, time­consuming process. Lacking a disk drive, the early computers depended on other kinds of storage: punch cards or paper tape. It should be understood that because there was no permanent storage, booting one of these machines often meant tog­gling a small “boot loader” [ [ ...]

Computer Networks

Schools, offices, and some homes are equipped with computer networks, which are wires that connect computers together and software and special hard­ware that allows the computers to communicate with each other. This allows people to send information to each other through their computers. But how does this really work? Computers use electricity to perform calculations [ [ ...]

Modern Computers: Representation

When applying a computer to a task or writing a program to deal with a type of data that seems to be non-numeric, the issue of how to represent the data on the computer invariably arises. Everything stored and manipulated on a computer has to be a number. What if the data is not numeric? [ [ ...]

Solving a Problem Using a Computer

The process of solving a problem using a computer begins with a detailed specification of the problem to be solved. Unless the problem is completely un­derstood, its solution on a computer is impossible. Then we examine the problem to see what methods that we know about and what programs we already have could be used [ [ ...]

Executing Python

Installing Python is not too difficult, and involves downloading the installer, running it, and perhaps configuring a few specific details. This process can be found in Appendix I. Once installed, there are a few variations that can be used with it, the simplest probably being the Python Graphical User Interface or GUI. If you are [ [ ...]

the Guess a Number Problem in Python

1. Guess a Number Games that involve guessing are common, and are sometimes used to resolve minor conflicts, such as who gets the next piece of cake or who gets the first kick at a football. It’s also sometimes a way to occupy time, and can simply be fun. How can we write a program [ [ ...]

the Rock-Paper-Scissors Problem in Python

1. Rock-Paper-Scissors This game is used to settle disputes and make random decisions. There are actually competitions where money is at stake. A televised contest in Las Vegas had a prize of $50,000. In this game, each of two players selects one item from the list (rock, paper, or scissors) in secret, and then both [ [ ...]

IF Statements in Python

An if statement begins with the word if, followed by an expression that evalu­ates to True or False, followed by a colon (:), then a series of statements that are executed if the expression is true. The names True and False are constants having the obvious meaning, and a variable that can take on these [ [ ...]

Documentation in Python

There are some problems with this program, but is does work. A large prob­lem is that it always choses the same number every time it is executed (that num­ber is 7). We will fix this issue later on. A less critical problem is that the program is undocumented; that is, there are no instructions to [ [ ...]

Rock-Paper-Scissors Again in Python

It is time to look at the rock-paper-scissors problem and see if it can be coded. It takes more steps, but it is no more complicated than the guess-a-number pro­gram. The code is the same. Select a choice from the three items rock, paper, or scissors. Save this choice in a variable named choice. A [ [ ...]

Types Are Dynamic (Advanced) in Python

To programmers who only program using Python, it would seem odd that a particular variable could have only one type and that it would have to be initially defined to have that type, but it is true. In Python, the type associated with a vari­able can change. For example, consider the statements: x =     10              [ [ ...]

Repetition in Python: The WHILE Statement

When using this repetition statement, the condition is tested at the top or be­ginning of the loop. If, upon that initial test, the condition is true, then the body of the loop is executed; otherwise, it is not, and the statement following the loop is executed. This means that it is possible that the code [ [ ...]

Repetition in Python: Rock-Paper-Scissors Revisited

This game needs a loop, and the previous implementation was not complete. If there is a tie, then the game has to be repeated, and a winner must be deter­mined. This means that the loop in this case is as follows: while there is no winner: This happens only when the player and the computer [ [ ...]

Repetition in Python: Counting Loops

Features of programming languages are provided because the designers know they are useful. The while loop is obviously useful, and is the only kind of loop required to implement a program. However, loops that involve counting a certain number of iterations are common, and adding syntax is valuable. Some­times a loop that executes, for example, [ [ ...]

Repetition in Python: Prime or Non-Prime

Here’s a game that can illustrate the use of a for loop, and some other ideas as well. The computer presents the player with large numbers, one at a time. The player has to guess whether each number is prime or non-prime. A prime number does not have any divisors except 1 and  itself. 3, [ [ ...]

Repetition in Python: Loops That Are Nested

Just as it is possible to have if statements nested within other if statements, it is possible, and even likely, to have a loop nested within another loop. An ex­ample of nested for loops is as follows: for i in range(0, 10) for j in range (0,  10) print (i,j) The print statement in this [ [ ...]

Repetition in Python: Draw a Histogram

A histogram is a kind of graph. It usually represents the frequency of the oc­currence of certain discrete values. Common examples include temperature as a function of the month, or histograms of income as a function of year, age, race, or gender. Drawing one involves knowing how many categories there are and what the numerical [ [ ...]