Glossary - Teach Your Kids to Code: A Parent-Friendly Guide to Python Programming (2015)

Teach Your Kids to Code: A Parent-Friendly Guide to Python Programming (2015)

Appendix D. Glossary

Many of the terms you encounter in learning to code are everyday words that you already understand. Some terms, though, are brand new or have special meaning to computer programmers. This glossary defines several of the newer terms you’ll come across in the book, as well as familiar words that take on new meanings in the world of coding.

algorithm

A set of steps for performing a task, like a recipe.

animation

The illusion of motion created when similar images are displayed quickly one after the other, as in a cartoon.

app

Short for application, a computer program that does something useful (or fun!).

append

To add something to the end; for example, adding letters onto the end of a string or adding elements to the end of a list or array.

argument

A value passed to a function; in the statement range(10), 10 is an argument.

array

An ordered list of values or objects, usually of the same type, accessed by their index, or position in the list.

assignment

Setting the value of a variable, as in x = 5, which assigns the value 5 to the variable x.

block

A group of programming statements.

Boolean

A value or expression that can be either true or false.

class

A template defining the functions and values to be contained in any objects of that type.

code

Statements or instructions written by a programmer in a language that computers can understand.

collision detection

Checking to see if two virtual objects are touching, or colliding, on the screen, like the ball and paddle in Pong.

concatenate

To combine two strings of text into a single string.

conditional expression

A statement that allows the computer to test a value and perform different actions depending on the outcome of that test.

constant

A named value in a computer program that stays the same, like math.pi (3.1415...).

declaration

A statement or group of statements that tell a computer what a variable or function name means.

element

A single item in a list or array.

event

An activity that a computer can detect, like a mouse click, value change, keypress, timer tick, and so on. Statements or functions that respond to events are called event handlers or event listeners.

expression

Any valid set of values, variables, operators, and functions that produces a value or result.

file

A collection of data or information stored by a computer on some kind of storage device, like a hard disk, DVD, or USB drive.

for loop

A programming statement that allows a block of code to be repeated for a given range of values.

frame

A single image in a moving sequence for animation, video, or computer graphics.

frames per second (fps)

The rate or speed that images are drawn on the screen in an animation, video game, or movie.

function

A named, reusable set of programming statements to perform a specific task.

import

To bring reusable code or data into a program from another program or module.

index

An element’s position in a list or array.

initialize

To give a variable or object its first, or initial, value.

input

Any data or information entered into a computer; input can come from a keyboard, mouse, microphone, digital camera, or any other input device.

iterative versioning

Repeatedly making small changes or improvements to a program and saving it as a new version, like Game1, Game2, and so on.

keyword

A special, reserved word that means something in a particular programming language.

list

A container for an ordered group of values or objects.

loop

A set of instructions that is repeated until a condition is reached.

module

A file or set of files with related variables, functions, and classes that can be reused in other programs.

nested loop

A loop inside another loop.

object

A variable containing information about a single instance of a class, such as a single sprite from the Sprite class.

operator

A symbol or set of symbols that represents an action or comparison and returns a result, such as +, -, *, //, <, >, ==, and so on.

parameter

An input variable to a function, specified in the function’s definition.

pixel

Short for picture element, the small dots of color that make up images on a computer screen.

program

A set of instructions written in a language computers can understand.

pseudorandom

A value in a sequence that seems to be random or unpredictable, and is random enough to simulate rolling dice or flipping coins.

random numbers

An unpredictable sequence of numbers evenly distributed over a certain range.

range

An ordered set of values between a known start and end value; in Python, the range function returns a sequence of values, such as 0 through 10.

RGB color

Short for red-green-blue color, a way of representing colors by the amount of red, green, and blue light that can be mixed to re-create each color.

shell

A text-based command line program that reads commands from the user and runs them; IDLE is Python’s shell.

sort

To put elements of a list or array in a certain order, such as alphabetical order.

string

A sequence of characters, which can include letters, numbers, symbols, punctuation, and spacing.

syntax

The spelling and grammar rules of a programming language.

transparency

In graphics, the ability to see through portions of an image.

variable

In a computer program, a named value that can change.

while loop

A programming statement that allows a block of code to be repeated as long as a condition is true.