Chapter 4

Question 1

instance

Answer 1

a member of a set. the TurtleWorld in this chapter is a member of the set of TurtleWorlds.

Question 2

loop

Answer 2

a part of a program that can execute repeatedly.

Question 3

encapsulation

Answer 3

the process of transforming a sequence of statements into a function definition.

Question 4

generalization

Answer 4

the process of replacing something unnecessarily specific (like a number) with something appropriately general (like a variable or parameter)

Question 5

keyword argument

Answer 5

an argument that includes the name of the parameter as a “keyword”.

Question 6

interface

Answer 6

a description of how to use a function, including the name and descriptions of the arguments and return value.

Question 7

refactoring

Answer 7

the process of modifying a working program to improve function interfaces and other qualities of the code.

Question 8

development plan

Answer 8

a process for writing programs.

Question 9

docstring

Answer 9

a string that appears in a function definition to document the function’s interface.

Question 10

precondition

Answer 10

a requirement that should be satisfied by the caller before a function starts.

Question 11

postcondition

Answer 11

a requirement that should be satisfied by the function before it ends.