Chapter 4: Hello, Little Turtles! Flashcards
attribute
Some state or value that belongs to a particular object. For example, tess has a color.
canvas
A surface within a window where drawing takes place.
control flow
See flow of execution in the next chapter.
for loop
A statement in Python for convenient repetition of statements in the body of the loop.
instance
An object that belongs to a class. tess and alex are different instances of the class Turtle
invoke
An object has methods. We use the verb invoke to mean activate the method. Invoking a method is done by putting parentheses after the method name, with some possible arguments. So wn.exitonclick() is an invocation of the exitonclick method.
iteration
A basic building block for algorithms (programs). It allows steps to be repeated. Sometimes called looping.
loop body
Any number of statements nested inside a loop. The nesting is indicated by the fact that the statements are indented under the for loop statement.
loop variable
A variable used as part of a for loop. It is assigned a different value on each iteration of the loop, and is used as part of the terminating condition of the loop,
method
A function that is attached to an object. Invoking or activating the method causes the object to respond in some way, e.g. forward is the method when we say tess.forward(100).
module
A file containing Python definitions and statements intended for use in other Python programs. The contents of a module are made available to the other program by using the import statement.
object
A “thing” to which a variable can refer. This could be a screen window, or one of the turtles you have created.
range
A built-in function in Python for generating sequences of integers. It is especially useful when we need to write a for loop that executes a fixed number of times.
sequential
The default behavior of a program. Step by step processing of algorithm.
state
The collection of attribute values that a specific data object maintains.
