Programming - Chapter 3 & 4

Attribute

Attribute

Some state or value that belongs to a particular object.

Canvas

Surface within window where drawing takes place.

Control Flow

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For Loop

Statement in python for convient repetition of statements in the body of the loop.

Loop Body

Any number of statements that are nested in the loop. Nesting is indicated by indentation under the loop statement.

Loop Variable

Variable used as part of a for loop. Assigned a different value each iteration of the loop.

Instance

Object of certain type/class . Ex. alex is a different instance of the class turtle.

Method

Function that is attached to an object. Invoking/activating the method makes the object to respond. (Ex. forward is the method when we say turtle.forward(100)).

Invoke

Invoke means to activate the method. Done by putting () after method name with arguments. (Ex. turtle.forward() is the invocation of the forward method)

Module

File containing Python definitions/statements make for use in other programs. Only avaliable after using import statement.

Object

Something to which a varialbe can refer to (screen window, a turtle, etc.)

Range

Built-in function in python for generating sequences of integers. Useful when we write a loop executing a fixed number of times.

Terminating Condition

Condition which causes a loop to stop repeating its body. When there are no more elements to assign to the loop variable.

Block

Group of consecutive statements with the same indentation.

Body

Block of statements in a compound statement following the header.?????

Boolean algebra

Rules for rearranging/reasoning abt Boolean expressions.

Boolean expression

Expression that is either true or false.

Boolean value

True and False. Values result when expression is evaluated by the interpreter.

Branch

One of the possible paths of the flow of execution determined by conditional execution.

Chained conditional

Conditional branch with more than two possible flows of execution. Written with if…elif…else…statements.

Comparison Operator

==, ≠, >, <, >=, and <=. Used to compare 2 values

Condition

Boolean expression in a conditional statement determining which branch is executed.

Conditional Statement

Statement controlling flow of execution depending on some condition. if, elif, else.

Logical operator

Operator combining Booleans: and, or, not.

Nesting

One program structure within another, like conditional statement inside a branch of another conditional statement.

Prompt

Visual cue telling user that the system is ready to accept input. The flashing thingy.

Truth table

Concise table of Boolean values that can describe semantics of an operator.

Type Conversion

Explicit function taking the value of one type and computing corresponding value of another type.

Algorithm

Step-by-step process for solving a category of problems.

Body

Statements inside a loop.

Bump

Slang for increment

Continue statement

Statement causing remainder of current iteration of a loop to be skipped. Flow of execution goes back to top of loop, evaluates condition, and if true, next iteration will begin.

Counter

Variable used to count smth, usually incremented with a loop.

Cursor

Invisible marker keeping track of where the next character is printed.

Decrement

Decrease by 1

Definite Iteration

Loop where there is an upper bound on the number of times the body will be executed. Usually best coded as a for loop.

Escape Sequence

Escape character, \, followed by printable characters to designate a nonprintable character.

Increment

Increase by 1.

Infinite loop

Loop where terminating condition is never satisfied so never ends.

Indefinite Iteration

Loop where we just need to keep going until a condition is met. While statement is used.

Initialization

Gives variable an initial value so it can be used later.

Iteration

Repeated execution of a set of programming statements.

Loop

Construct allowing us to repeatedly execute a statement or group of statements until a terminating condition is satisfied.

Loop Variable

Variable used as part of the terminating condition of a loop.

Meta-Notation

Extra symbols/notation helping describe other notation. [], …, italics, bold, etc. to describe python syntax.

Middle-Test Loop

Loop executing some of the body then testing exit condition and can execute some more of the body. While and break.

Pre-Test Loop

Loop that tests before deciding whether to execute its body.

Tab

Causes cursor to move to the next tab stop on current line.

Trichotomy

Seeing which expressions numbers make true: a<b, a>b, a==b.

Trace

Follow flow of execution of a program by hand.

Boolean Function

Function returning a Boolean value. True or False.

Chatterbox Function

Function interacting with the user (print or input) when it shouldn’t. Silent functions converting input arguments into outputs are better.

Composition

Calling one function from within the body of another or using return value of one function as an argument to the call of another.

Dead Code

Part of the program can never be executed, often because it appears after a return statement

Fruitful Function

Function that yields a return value instead of none

Incremental development

Program development plan intended to simplify debugging by adding and testing only a small amt of code at a time.

None

Special python value. One use in python is that it is returned by functions that do not execute a return statement with a return argument.

Return value

Value provided as the result of a function call

Scaffolding

Code used during development used to help debugging and development.

Temporary Variable

Variable used to store intermediate value in complex calculation