Starting Out With Python - Third Edition

Front 1

What is a program?

Back 1

A program is a set of instructions that a computer follows to perform a task.

Hint 1

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 2

What is hardware?

Back 2

Hardware is all the physical devices, or components, of which a computer is made.

Hint 2

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 3

List the five major components of a computer system.

Back 3

The central processing unit (CPU), main memory, secondary storage devices, input devices, and output devices

Hint 3

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 4

What part of the computer actually runs programs?

Back 4

The CPU

Hint 4

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 5

What part of the computer serves as a work area to store a program and its data while the program is running?

Back 5

Main memory

Hint 5

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 6

What part of the computer holds data for long periods of time, even when there is no power to the computer?

Back 6

Secondary storage

Hint 6

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 7

What part of the computer collects data from people and from other devices?

Back 7

Input device

Hint 7

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 8

What part of the computer formats and presents data for people or other devices?

Back 8

Output device

Hint 8

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 9

What fundamental set of programs control the internal operations of the computer’s hardware?

Back 9

The operating system

Hint 9

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 10

What do you call a program that performs a specialized task, such as a virus scanner, a file compression program, or a data backup program?

Back 10

A utility program

Hint 10

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 11

Word processing programs, spreadsheet programs, email programs, web browsers, and game programs belong to what category of software?

Back 11

Application software

Hint 11

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 12

What amount of memory is enough to store a letter of the alphabet or a small number?

Back 12

One byte

Hint 12

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 13

What do you call a tiny “switch” that can be set to either on or off?

Back 13

A bit

Hint 13

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 14

In what numbering system are all numeric values written as sequences of 0s and 1s?

Back 14

The binary numbering system

Hint 14

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 15

What is the purpose of ASCII?

Back 15

It is an encoding scheme that uses a set of 128 numeric codes to represent the English letters, various punctuation marks, and other characters. These numeric codes are used to store characters in a computer’s memory. (ASCII stands for the American Standard Code for Information Interchange.)

Hint 15

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 16

What encoding scheme is extensive enough to represent the characters of many of the languages in the world?

Back 16

Unicode

Hint 16

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 17

What do the terms “digital data” and “digital device” mean?

Back 17

Digital data is data that is stored in binary, and a digital device is any device that works with binary data.

Hint 17

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 18

A CPU understands instructions that are written only in what language?

Back 18

Machine language

Hint 18

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 19

A program has to be copied into what type of memory each time the CPU executes it?

Back 19

Main memory, or RAM

Hint 19

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 20

When a CPU executes the instructions in a program, it is engaged in what process?

Back 20

The fetch-decode-execute cycle

Hint 20

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 21

What is assembly language?

Back 21

It is an alternative to machine language. Instead of using binary numbers for instructions, assembly language uses short words that are known as mnemonics.

Hint 21

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 22

What type of programming language allows you to create powerful and complex programs without knowing how the CPU works?

Back 22

A high-level language

Hint 22

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 23

Each language has a set of rules that must be strictly followed when writing a program. What is this set of rules called?

Back 23

Syntax

Hint 23

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 24

What do you call a program that translates a high-level language program into a separate machine language program?

Back 24

A compiler

Hint 24

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 25

What do you call a program that both translates and executes the instructions in a high-level language program?

Back 25

An interpreter

Hint 25

Ch1 Using interactive Mode in IDLE, p. 23Performing Exercise 2, p.28

Front 26

What type of mistake is usually caused by misspelled keyword, a missing punctuation character, or the incorrect use of an operator?

Back 26

A syntax error

Hint 26

Ch2 The print Function, p.36Reading Input from the keyboard, p.49The Sales Predition Problem, p.77

Front 27

Who is a programmer’s customer?

Back 27

Any person, group, or organization that is asking you to write a program

Hint 27

Ch2 The print Function, p.36Reading Input from the keyboard, p.49The Sales Predition Problem, p.77

Front 28

What is a software requirement?

Back 28

A single function that the program must perform in order to satisfy the customer

Hint 28

Ch2 The print Function, p.36Reading Input from the keyboard, p.49The Sales Predition Problem, p.77

Front 29

What is an algorithm?

Back 29

A set of well-defined logical steps that must be taken to perform a task

Hint 29

Ch2 The print Function, p.36Reading Input from the keyboard, p.49The Sales Predition Problem, p.77

Front 30

What is pseudocode?

Back 30

An informal language that has no syntax rules and is not meant to be compiled or executed. Instead, programmers use pseudocode to create models, or “mock-ups,” of programs.

Hint 30

Ch2 The print Function, p.36Reading Input from the keyboard, p.49The Sales Predition Problem, p.77

Front 31

What is a flowchart?

Back 31

A diagram that graphically depicts the steps that take place in a program

Hint 31

Ch2 The print Function, p.36Reading Input from the keyboard, p.49The Sales Predition Problem, p.77

Front 32

What do each of the following symbols mean in a flowchart? • Oval • Parallelogram • Rectangle

Back 32

Ovals are terminal symbols. Parallelograms are either output or input symbols. Rectangles are processing symbols.

Hint 32

Ch2 The print Function, p.36Reading Input from the keyboard, p.49The Sales Predition Problem, p.77

Front 33

Write a statement that displays your name.

Back 33

print('Jimmy Smith')

Hint 33

Ch2 The print Function, p.36Reading Input from the keyboard, p.49The Sales Predition Problem, p.77

Front 34

Write a statement that displays the following text: Python's the best!

Back 34

print("Python's the best!”)

Hint 34

Ch2 The print Function, p.36Reading Input from the keyboard, p.49The Sales Predition Problem, p.77

Front 35

Write a statement that displays the following text: The cat said "meow."

Back 35

print('The cat said "meow”')

Hint 35

Ch2 The print Function, p.36Reading Input from the keyboard, p.49The Sales Predition Problem, p.77

Front 36

What is a variable?

Back 36

A name that references a value in the computer’s memory

Hint 36

Ch2 The print Function, p.36Reading Input from the keyboard, p.49The Sales Predition Problem, p.77

Front 37

Which of the following are illegal variable names in Python, and why? x 99bottles july2009 theSalesFigureForFiscalYear r&d grade_report

Back 37

99bottles is illegal because it begins with a number. r&d is illegal because the & character is not allowed.

Hint 37

Ch2 The print Function, p.36Reading Input from the keyboard, p.49The Sales Predition Problem, p.77

Front 38

Is the variable name Sales the same as sales? Why or why not?

Back 38

No, it is not because variable names are case sensitive.

Hint 38

Ch2 The print Function, p.36Reading Input from the keyboard, p.49The Sales Predition Problem, p.77

Front 39

Is the following assignment statement valid or invalid? If it is invalid, why? 72 = amount

Back 39

It is invalid because the variable that is receiving the assignment (in this case amount ) must appear on the left side of the = operator.

Hint 39

Ch2 The print Function, p.36Reading Input from the keyboard, p.49The Sales Predition Problem, p.77

Front 40

What will the following code display? val = 99 print('The value is', 'val')

Back 40

The value is val.

Hint 40

Ch2 The print Function, p.36Reading Input from the keyboard, p.49The Sales Predition Problem, p.77

Front 41

Look at the following assignment statements: value1 = 99 value2 = 45.9 value3 = 7.0 value4 = 7 value5 = 'abc' After these statements execute, what is the Python data type of the values referenced by each variable?

Back 41

value1 will reference an int . value2 will reference a float . value3 will reference a float . value4 will reference an int . value5 will reference an str (string).

Hint 41

Ch2 The print Function, p.36Reading Input from the keyboard, p.49The Sales Predition Problem, p.77

Front 42

What will be displayed by the following program? my_value = 99 my_value = 0 print(my_value)

Back 42

0

Hint 42

Ch2 The print Function, p.36Reading Input from the keyboard, p.49The Sales Predition Problem, p.77

Front 43

You need the user of a program to enter a customer’s last name. Write a statement that prompts the user to enter this data and assigns the input to a variable.

Back 43

last_name = input("Enter the customer's last name: ”)

Hint 43

Ch2 The print Function, p.36Reading Input from the keyboard, p.49The Sales Predition Problem, p.77

Front 44

You need the user of a program to enter the amount of sales for the week. Write a statement that prompts the user to enter this data and assigns the input to a variable.

Back 44

sales = float(input('Enter the sales for the week: '))

Hint 44

Ch2 The print Function, p.36Reading Input from the keyboard, p.49The Sales Predition Problem, p.77

Front 45

Complete the following table by writing the value of each expression in the Value column. Expression Value 6 + 3 * 5 ______ 12 / 2 - 4 ______ 9 + 14 * 2 - 6 ______ (6 + 2) * 3 ______ 14 / (11 - 4) ______ 9 + 12 * (8 - 3) ______

Back 45

Here is the completed table: Expression Value 6 + 3 * 5 21 12 / 2 − 4 29 + 14 * 2 − 6 31(6 + 2) * 3 2414 / (11 − 4) 29 + 12 * (8 − 3) 692.20 42.21 1

Hint 45

Ch2 The print Function, p.36Reading Input from the keyboard, p.49The Sales Predition Problem, p.77

Front 46

What value will be assigned to result after the following statement executes? result = 9 // 2

Back 46

4

Hint 46

Ch2 The print Function, p.36Reading Input from the keyboard, p.49The Sales Predition Problem, p.77

Front 47

What value will be assigned to result after the following statement executes? result = 9 % 2

Back 47

1

Hint 47

Ch2 The print Function, p.36Reading Input from the keyboard, p.49The Sales Predition Problem, p.77

Front 48

What is a control structure?

Back 48

A logical design that controls the order in which a set of statements execute

Hint 48

Ch3 the if Statement, p.81the if-else Statement, p. 90The Areas of Rectangles Problem,p.115

Front 49

What is a decision structure?

Back 49

It is a program structure that can execute a set of statements only under certain circumstances.

Hint 49

Ch3 the if Statement, p.81the if-else Statement, p. 90The Areas of Rectangles Problem,p.115

Front 50

What is a single alternative decision structure?

Back 50

A decision structure that provides a single alternative path of execution. If the condition that is being tested is true, the program takes the alternative path.

Hint 50

Ch3 the if Statement, p.81the if-else Statement, p. 90The Areas of Rectangles Problem,p.115

Front 51

What is a Boolean expression?

Back 51

An expression that can be evaluated as either true or false

Hint 51

Ch3 the if Statement, p.81the if-else Statement, p. 90The Areas of Rectangles Problem,p.115

Front 52

What types of relationships between values can you test with relational operators?

Back 52

You can determine whether one value is greater than, less than, greater than or equal to, less than or equal to, equal to, or not equal to another value.

Hint 52

Ch3 the if Statement, p.81the if-else Statement, p. 90The Areas of Rectangles Problem,p.115

Front 53

Write an if statement that assigns 0 to x if y is equal to 20.

Back 53

if y == 20: x = 0

Hint 53

Ch3 the if Statement, p.81the if-else Statement, p. 90The Areas of Rectangles Problem,p.115

Front 54

Write an if statement that assigns 0.2 to commissionRate if sales is greater than or equal to 10000.

Back 54

if sales >= 10000: commissionRate = 0.2

Hint 54

Ch3 the if Statement, p.81the if-else Statement, p. 90The Areas of Rectangles Problem,p.115

Front 55

How does a dual alternative decision structure work?

Back 55

A dual alternative decision structure has two possible paths of execution; one path is taken if a condition is true, and the other path is taken if the condition is false.

Hint 55

Ch3 the if Statement, p.81the if-else Statement, p. 90The Areas of Rectangles Problem,p.115

Front 56

What statement do you use in Python to write a dual alternative decision structure?

Back 56

if - else

Hint 56

Ch3 the if Statement, p.81the if-else Statement, p. 90The Areas of Rectangles Problem,p.115

Front 57

When you write an if-else statement, under what circumstances do the statements that appear after the else clause execute?

Back 57

When the condition is false

Hint 57

Ch3 the if Statement, p.81the if-else Statement, p. 90The Areas of Rectangles Problem,p.115

Front 58

What would the following code display? if 'z' < 'a': print('z is less than a.')else: print('z is not less than a.')

Back 58

z is not less than a.

Hint 58

Ch3 the if Statement, p.81the if-else Statement, p. 90The Areas of Rectangles Problem,p.115

Front 59

What would the following code display?s1 = 'New York' s2 = 'Boston' if s1 > s2: print(s2) print(s1)else: print(s1) print(s2)

Back 59

Boston New York

Hint 59

Ch3 the if Statement, p.81the if-else Statement, p. 90The Areas of Rectangles Problem,p.115

Front 60

Convert the following code to an if-elif-else statement: if number == 1: print('One') else: if number == 2: print('Two') else: if number == 3: print('Three') else: print('Unknown')

Back 60

if number == 1: print('One') elif number == 2: print('Two') elif number == 3: print('Three') else: print('Unknown')

Hint 60

Ch3 the if Statement, p.81the if-else Statement, p. 90The Areas of Rectangles Problem,p.115

Front 61

What is a compound Boolean expression?

Back 61

It is an expression that is created by using a logical operator to combine two Boolean subexpressions.

Hint 61

Ch3 the if Statement, p.81the if-else Statement, p. 90The Areas of Rectangles Problem,p.115

Front 62

The following truth table shows various combinations of the values true and false connected by a logical operator. Complete the table by circling T or F to indicate whether the result of such a combination is true or false. Logical Expression Result (circle T or F) True and False T F True and True T F False and True T F False and False T F True or False T F True or True T F False or True T F False or False T F not True T F not False T F

Back 62

F T F F T T T F F T

Hint 62

Ch3 the if Statement, p.81the if-else Statement, p. 90The Areas of Rectangles Problem,p.115

Front 63

Assume the variables a = 2, b = 4, and c = 6. Circle the T or F for each of the following conditions to indicate whether its value is true or false.

a == 4 or b > 2 T F

6 <= c and a > 3 T F

1 != b and c != 3 T F

a >= -1 or a <= b T F

not (a > 2) T F

Back 63

T F T T T

Hint 63

Ch3 the if Statement, p.81the if-else Statement, p. 90The Areas of Rectangles Problem,p.115

Front 64

Explain how short-circuit evaluation works with the and and or operators.

Back 64

The and operator: if the expression on the left side of the and operator is false, the expression on the right side will not be checked. the or operator: if the expression on the left side of the or operator is true, the expression on the right side will not be checked.

Hint 64

Ch3 the if Statement, p.81the if-else Statement, p. 90The Areas of Rectangles Problem,p.115

Front 65

Write an if statement that displays the message “The number is valid” if the value referenced by speed is within the range 0 through 200.

Back 65

if speed >= 0 and speed <= 200: print('The number is valid')

Hint 65

Ch3 the if Statement, p.81the if-else Statement, p. 90The Areas of Rectangles Problem,p.115

Front 66

Write an if statement that displays the message “The number is not valid” if the value referenced by speed is outside the range 0 through 200.

Back 66

if speed < 0 or speed > 200: print('The number is not valid')

Hint 66

Ch3 the if Statement, p.81the if-else Statement, p. 90The Areas of Rectangles Problem,p.115

Front 67

What values can you assign to a bool variable?

Back 67

True or False

Hint 67

Ch3 the if Statement, p.81the if-else Statement, p. 90The Areas of Rectangles Problem,p.115

Front 68

What is a flag variable?

Back 68

A variable that signals when some condition exists in the program

Hint 68

Ch3 the if Statement, p.81the if-else Statement, p. 90The Areas of Rectangles Problem,p.115

Front 69

What is a repetition structure?

Back 69

A structure that causes a section of code to repeat

Hint 69

Ch4 The whileloop,p.122The for loop, p.130The Bug Collector Problem, p.161

Front 70

What is a condition-controlled loop?

Back 70

A loop that uses a true/false condition to control the number of times that it repeats

Hint 70

Ch4 The whileloop,p.122The for loop, p.130The Bug Collector Problem, p.161

Front 71

What is a count-controlled loop?

Back 71

A loop that repeats a specific number of times

Hint 71

Ch4 The whileloop,p.122The for loop, p.130The Bug Collector Problem, p.161

Front 72

What is a loop iteration?

Back 72

An execution of the statements in the body of the loop

Hint 72

Ch4 The whileloop,p.122The for loop, p.130The Bug Collector Problem, p.161

Front 73

Does the while loop test its condition before or after it performs an iteration?

Back 73

Before

Hint 73

Ch4 The whileloop,p.122The for loop, p.130The Bug Collector Problem, p.161

Front 74

How many times will 'Hello World' be printed in the following program? count = 10 while count < 1: print('Hello World')

Back 74

None. The condition count < 0 will be false to begin with.

Hint 74

Ch4 The whileloop,p.122The for loop, p.130The Bug Collector Problem, p.161

Front 75

What is an infinite loop?

Back 75

A loop that has no way of stopping and repeats until the program is interrupted.

Hint 75

Ch4 The whileloop,p.122The for loop, p.130The Bug Collector Problem, p.161

Front 76

Rewrite the following code so it calls the range function instead of using the list [0, 1, 2, 3, 4, 5]. for x in [0, 1, 2, 3, 4, 5]: print('I love to program!')

Back 76

for x in range(6): print('I love to program!')

Hint 76

Ch4 The whileloop,p.122The for loop, p.130The Bug Collector Problem, p.161

Front 77

What will the following code display? for number in range(6): print(number)

Back 77

0 1 2 3 5

Hint 77

Ch4 The whileloop,p.122The for loop, p.130The Bug Collector Problem, p.161

Front 78

What will the following code display? for number in range(2, 6): print(number)

Back 78

2 3 4 5

Hint 78

Ch4 The whileloop,p.122The for loop, p.130The Bug Collector Problem, p.161

Front 79

What will the following code display? for number in range(0, 501, 100): print(number)

Back 79

0 100 200 300 400 500

Hint 79

Ch4 The whileloop,p.122The for loop, p.130The Bug Collector Problem, p.161

Front 80

What will the following code display? for number in range(10, 5, -1): print(number)

Back 80

10 9 8 7 6

Hint 80

Ch4 The whileloop,p.122The for loop, p.130The Bug Collector Problem, p.161

Front 81

What is an accumulator?

Back 81

A variable that is used to accumulate the total of a series of numbers

Hint 81

Ch4 The whileloop,p.122The for loop, p.130The Bug Collector Problem, p.161

Front 82

Should an accumulator be initialized to any specific value? Why or why not?

Back 82

Yes, it should be initialized with the value 0. This is because values are added to the accumulator by a loop. If the accumulator does not start at the value 0, it will not contain the correct total of the numbers that were added to it when the loop ends.

Hint 82

Ch4 The whileloop,p.122The for loop, p.130The Bug Collector Problem, p.161

Front 83

What will the following code display? total = 0 for count in range(1, 6): total = total + count print(total)

Back 83

15

Hint 83

Ch4 The whileloop,p.122The for loop, p.130The Bug Collector Problem, p.161

Front 84

What will the following code display? number1 = 10 number2 = 5 number1 = number1 + number2 print(number1) print(number2)

Back 84

15 5

Hint 84

Ch4 The whileloop,p.122The for loop, p.130The Bug Collector Problem, p.161

Front 85

Rewrite the following statements using augmented assignment operators: a) quantity = quantity + 1 b) days_left = days_left - 5 c) price = price * 10 d) price = price / 2

Back 85

a) quantity += 1 b) days_left −= 5 c) price *= 10 d) price /= 2

Hint 85

Ch4 The whileloop,p.122The for loop, p.130The Bug Collector Problem, p.161

Front 86

What is a sentinel?

Back 86

A sentinel is a special value that marks the end of a list of items.

Hint 86

Ch4 The whileloop,p.122The for loop, p.130The Bug Collector Problem, p.161

Front 87

Why should you take care to choose a distinctive value as a sentinel?

Back 87

A sentinel value must be unique enough that it will not be mistaken as a regular value in the list.

Hint 87

Ch4 The whileloop,p.122The for loop, p.130The Bug Collector Problem, p.161

Front 88

What does the phrase “garbage in, garbage out” mean?

Back 88

It means that if bad data (garbage) is provided as input to a program, the program will produce bad data (garbage) as output.

Hint 88

Ch4 The whileloop,p.122The for loop, p.130The Bug Collector Problem, p.161

Front 89

Give a general description of the input validation process.

Back 89

When input is given to a program, it should be inspected before it is processed. If the input is invalid, then it should be discarded and the user should be prompted to enter the correct data.

Hint 89

Ch4 The whileloop,p.122The for loop, p.130The Bug Collector Problem, p.161

Front 90

Describe the steps that are generally taken when an input validation loop is used to validate data.

Back 90

The input is read, and then a pretest loop is executed. If the input data is invalid, the body of the loop executes. In the body of the loop, an error message is displayed so the user will know that the input was invalid, and then the input read again. The loop repeats as long as the input is invalid.

Hint 90

Ch4 The whileloop,p.122The for loop, p.130The Bug Collector Problem, p.161

Front 91

What is a priming read? What is its purpose?

Back 91

It is the input operation that takes place just before an input validation loop. The purpose of the priming read is to get the first input value.

Hint 91

Ch4 The whileloop,p.122The for loop, p.130The Bug Collector Problem, p.161

Front 92

If the input that is read by the priming read is valid, how many times will the input validation loop iterate?

Back 92

None

Hint 92

Ch4 The whileloop,p.122The for loop, p.130The Bug Collector Problem, p.161

Front 93

What is a function?

Back 93

A function is a group of statements that exist within a program for the purpose of performing a specific task.

Hint 93

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 94

What is meant by the phrase “divide and conquer?”

Back 94

A large task is divided into several smaller tasks that are easily performed.

Hint 94

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 95

How do functions help you reuse code in a program?

Back 95

If a specific operation is performed in several places in a program, a function can be written once to perform that operation and then be executed any time it is needed.

Hint 95

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 96

How can functions make the development of multiple programs faster?

Back 96

Functions can be written for the common tasks that are needed by the different programs. Those functions can then be incorporated into each program that needs them.

Hint 96

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 97

How can functions make it easier for programs to be developed by teams of programmers?

Back 97

When a program is developed as a set of functions in which each performs an individual task, then different programmers can be assigned the job of writing different functions.

Hint 97

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 98

A function definition has what two parts?

Back 98

A function definition has two parts: a header and a block. The header indicates the starting point of the function, and the block is a list of statements that belong to the function.

Hint 98

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 99

What does the phrase “calling a function” mean?

Back 99

To call a function means to execute the function.

Hint 99

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 100

When a function is executing, what happens when the end of the function’s block is reached?

Back 100

When the end of the function is reached, the computer returns back to the part of the program that called the function, and the program resumes execution at that point.

Hint 100

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 101

Why must you indent the statements in a block?

Back 101

Because the Python interpreter uses the indentation to determine where a block begins and ends

Hint 101

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 102

What is a local variable? How is access to a local variable restricted?

Back 102

A local variable is a variable that is declared inside a function. It belongs to the function in which it is declared, and only statements in the same function can access it.

Hint 102

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 103

What is a variable’s scope?

Back 103

The part of a program in which a variable may be accessed

Hint 103

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 104

Is it permissible for a local variable in one function to have the same name as a local variable in a different function?

Back 104

Yes, it is permissible.

Hint 104

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 105

What are the pieces of data that are passed into a function called?

Back 105

Arguments

Hint 105

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 106

What are the variables that receive pieces of data in a function called?

Back 106

Parameters

Hint 106

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 107

What is a parameter variable’s scope?

Back 107

A parameter variable’s scope is the entire function in which the parameter is declared.

Hint 107

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 108

When a parameter is changed, does this affect the argument that was passed into the parameter?

Back 108

No, it does not.

Hint 108

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 109

The following statements call a function named show_data. Which of the statements passes arguments by position, and which passes keyword arguments? a) show_data(name='Kathryn', age=25) b) show_data('Kathryn', 25)

Back 109

a. passes by keyword argument b. passes by position

Hint 109

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 110

What is the scope of a global variable?

Back 110

The entire program

Hint 110

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 111

Give one good reason that you should not use global variables in a program.

Back 111

Here are three: • Global variables make debugging difficult. Any statement in a program can change the value of a global variable. If you find that the wrong value is being stored in a global variable, you have to track down every statement that accesses it to determine where the bad value is coming from. In a program with thousands of lines of code, this can be difficult. • Functions that use global variables are usually dependent on those variables. If you want to use such a function in a different program, you will most likely have to redesign it so it does not rely on the global variable. • Global variables make a program hard to understand. A global variable can be modified by any statement in the program. If you are to understand any part of the program that uses a global variable, you have to be aware of all the other parts of the program that access the global variable.

Hint 111

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 112

What is a global constant? Is it permissible to use global constants in a program?

Back 112

A global constant is a name that is available to every function in the program. It is permissible to use global constants. Because their value cannot be changed during the program’s execution, you do not have to worry about its value being altered.

Hint 112

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 113

How does a value-returning function differ from the simple functions we discussed in Chapter 3?

Back 113

The difference is that a value returning function returns a value back to the statement that called it. A simple function does not return a value.

Hint 113

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 114

What is a library function?

Back 114

A prewritten function that performs some commonly needed task

Hint 114

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 115

Why are library functions like “black boxes”?

Back 115

The term “black box” is used to describe any mechanism that accepts input, performs some operation (that cannot be seen) using the input, and produces output.

Hint 115

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 116

What does the following statement do? x = random.randint(1, 100)

Back 116

It assigns a random integer in the range of 1 through 100 to the variable x .

Hint 116

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 117

What does the following statement do? print(random.randint(1, 20))

Back 117

It prints a random integer in the range of 1 through 20.

Hint 117

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 118

What does the following statement do? print(random.randrange(10, 20))

Back 118

It prints a random integer in the range of 10 through 19.

Hint 118

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 119

What does the following statement do? print(random.random())

Back 119

It prints a random floating-point number in the range of 0.0 up to, but not including, 1.0.

Hint 119

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 120

What does the following statement do? print(random.uniform(0.1, 0.5))

Back 120

It prints a random floating-point number in the range of 0.1 through 0.5.

Hint 120

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 121

When the random module is imported, what does it use as a seed value for random number generation?

Back 121

It uses the system time, retrieved from the computer’s internal clock.

Hint 121

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 122

What happens if the same seed value is always used for generating random numbers?

Back 122

If the same seed value were always used, the random number functions would always generate the same series of pseudorandom numbers.

Hint 122

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 123

What is the purpose of the return statement in a function?

Back 123

It returns a value back to the part of the program that called it.

Hint 123

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 124

Look at the following function definition: def do_something(number): return number * 2 a. What is the name of the function? b. What does the function do? c. Given the function definition, what will the following statement display? print(do_something(10))

Back 124

a) do_something b) It returns a value that is twice the argument passed to it. c) 20

Hint 124

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 125

What is a Boolean function?

Back 125

A function that returns either True or False

Hint 125

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 126

What import statement do you need to write in a program that uses the math module.

Back 126

import math

Hint 126

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 127

Write a statement that uses a math module function to get the square root of 100 and assigns it to a variable.

Back 127

square_root = math.sqrt(100)

Hint 127

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 128

Write a statement that uses a math module function to convert 45 degrees to radians and assigns the value to a variable.

Back 128

angle = math.radians(45)

Hint 128

Ch5 Defining and calling a function, p.168Passing Arguments to a function, p.181writing a Value-returning Function, p.206The Kilometer Converter Problem, p.229The Feet to Inches Problems, p.230

Front 129

What is an output file?

Back 129

A file to which a program writes data. It is called an output file because the program sends output to it.

Hint 129

Ch6 Using Loops to Process Files, p.252File Display, p.288

Front 130

What is an input file?

Back 130

A file from which a program reads data. It is called an input file because the program receives input from it.

Hint 130

Ch6 Using Loops to Process Files, p.252File Display, p.288

Front 131

What three steps must be taken by a program when it uses a file?

Back 131

(1) Open the file. (2) Process the file. (3) Close the file.

Hint 131

Ch6 Using Loops to Process Files, p.252File Display, p.288

Front 132

In general, what are the two types of files? What is the difference between these two types of files?

Back 132

Text and binary. A text file contains data that has been encoded as text using a scheme such as ASCII. Even if the file contains numbers, those numbers are stored in the file as a series of characters. As a result, the file may be opened and viewed in a text editor such as Notepad. A binary file contains data that has not been converted to text. As a consequence, you cannot view the contents of a binary file with a text editor.

Hint 132

Ch6 Using Loops to Process Files, p.252File Display, p.288

Front 133

What are the two types of file access? What is the difference between these two?

Back 133

Sequential and direct access. When you work with a sequential access file, you access data from the beginning of the file to the end of the file. When you work with a direct access file, you can jump directly to any piece of data in the file without reading the data that comes before it.

Hint 133

Ch6 Using Loops to Process Files, p.252File Display, p.288

Front 134

When writing a program that performs an operation on a file, what two file associated names do you have to work with in your code?

Back 134

The file’s name on the disk and the name of a variable that references a file object.

Hint 134

Ch6 Using Loops to Process Files, p.252File Display, p.288

Front 135

If a file already exists what happens to it if you try to open it as an output file (using the 'w' mode)?

Back 135

The file’s contents are erased.

Hint 135

Ch6 Using Loops to Process Files, p.252File Display, p.288

Front 136

What is the purpose of opening a file?

Back 136

Opening a file creates a connection between the file and the program. It also creates an association between the file and a file object.

Hint 136

Ch6 Using Loops to Process Files, p.252File Display, p.288

Front 137

What is the purpose of closing a file?

Back 137

Closing a file disconnects the program from the file.

Hint 137

Ch6 Using Loops to Process Files, p.252File Display, p.288

Front 138

What is a file’s read position? Initially, where is the read position when an input file is opened?

Back 138

A file’s read position marks the location of the next item that will be read from the file. When an input file is opened, its read position is initially set to the first item in the file.

Hint 138

Ch6 Using Loops to Process Files, p.252File Display, p.288

Front 139

In what mode do you open a file if you want to write data to it, but you do not want to erase the file’s existing contents? When you write data to such a file, to what part of the file is the data written?

Back 139

You open the file in append mode. When you write data to a file in append mode, the data is written to the end of the file’s existing contents.

Hint 139

Ch6 Using Loops to Process Files, p.252File Display, p.288

Front 140

Write a short program that uses a for loop to write the numbers 1 through 10 to a file.

Back 140

outfile = open('numbers.txt', 'w') for num in range(1, 11): outfile.write(str(num) + '\n') outfile.close()

Hint 140

Ch6 Using Loops to Process Files, p.252File Display, p.288

Front 141

What does it mean when the readline method returns an empty string?

Back 141

The readline method returns an empty string ( '' ) when it has attempted to read beyond the end of a file.

Hint 141

Ch6 Using Loops to Process Files, p.252File Display, p.288

Front 142

Assume that the file data.txt exists and contains several lines of text. Write a short program using the while loop that displays each line in the file.

Back 142

infile = open('numbers.txt', 'r') line = infile.readline() while line != '': print(line) line = infile.readline() infile.close()

Hint 142

Ch6 Using Loops to Process Files, p.252File Display, p.288

Front 143

Revise the program that you wrote for Checkpoint 6.14 to use the for loop instead of the while loop.

Back 143

infile = open('data.txt', 'r') for line in infile: print(line) infile.close()

Hint 143

Ch6 Using Loops to Process Files, p.252File Display, p.288

Front 144

What is a record? What is a field?

Back 144

A record is a complete set of data that describes one item, and a field is a single piece of data within a record.

Hint 144

Ch6 Using Loops to Process Files, p.252File Display, p.288

Front 145

Describe the way that you use a temporary file in a program that modifies a record in a sequential access file.

Back 145

You copy all the original file’s records to the temporary file, but when you get to the record that is to be modified, you do not write its old contents to the temporary file. Instead, you write its new, modified values to the temporary file. Then, you finish copying any remaining records from the original file to the temporary file.

Hint 145

Ch6 Using Loops to Process Files, p.252File Display, p.288

Front 146

Describe the way that you use a temporary file in a program that deletes a record from a sequential file.

Back 146

You copy all the original file’s records to the temporary file, except for the record that is to be deleted. The temporary file then takes the place of the original file. You delete the original file and rename the temporary file, giving it the name that the original file had on the computer’s disk.

Hint 146

Ch6 Using Loops to Process Files, p.252File Display, p.288

Front 147

Briefly describe what an exception is.

Back 147

An exception is an error that occurs while a program is running. In most cases, an exception causes a program to abruptly halt.

Hint 147

Ch6 Using Loops to Process Files, p.252File Display, p.288

Front 148

If an exception is raised and the program does not handle it with a try/except statement, what happens?

Back 148

The program halts.

Hint 148

Ch6 Using Loops to Process Files, p.252File Display, p.288

Front 149

What type of exception does a program raise when it tries to open a nonexistent file?

Back 149

IOError

Hint 149

Ch6 Using Loops to Process Files, p.252File Display, p.288

Front 150

What type of exception does a program raise when it uses the float function to convert a non-numeric string to a number?

Back 150

ValueError

Hint 150

Ch6 Using Loops to Process Files, p.252File Display, p.288

Front 151

What will the following code display? numbers = [1, 2, 3, 4, 5] numbers[2] = 99 print(numbers)

Back 151

[1, 2, 99, 4, 5]

Hint 151

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 152

What will the following code display? numbers = list(range(3)) print(numbers)

Back 152

[0, 1, 2]

Hint 152

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 153

What will the following code display? numbers = [10] * 5 print(numbers)

Back 153

[10, 10, 10, 10, 10]

Hint 153

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 154

What will the following code display? numbers = list(range(1, 10, 2))for n in numbers: print(n)

Back 154

1 3 5 7 9

Hint 154

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 155

What will the following code display? numbers = [1, 2, 3, 4, 5] print(numbers[-2])

Back 155

4

Hint 155

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 156

How do you find the number of elements in a list?

Back 156

Use the built-in len function.

Hint 156

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 157

What will the following code display? numbers1 = [1, 2, 3] numbers2 = [10, 20, 30] numbers3 = numbers1 + numbers2 print(numbers1) print(numbers2) print(numbers3)

Back 157

[1, 2, 3] [10, 20, 30] [1, 2, 3, 10, 20, 30]

Hint 157

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 158

What will the following code display? numbers1 = [1, 2, 3] numbers2 = [10, 20, 30] numbers2 += numbers1 print(numbers1) print(numbers2)

Back 158

[1, 2, 3] [10, 20, 30, 1, 2, 3]

Hint 158

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 159

What will the following code display? numbers = [1, 2, 3, 4, 5] my_list = numbers[1:3] print(my_list)

Back 159

[2, 3]

Hint 159

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 160

What will the following code display? numbers = [1, 2, 3, 4, 5] my_list = numbers[1:] print(my_list)

Back 160

[2, 3]

Hint 160

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 161

What will the following code display? numbers = [1, 2, 3, 4, 5] my_list = numbers[:1] print(my_list)

Back 161

[1]

Hint 161

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 162

What will the following code display? numbers = [1, 2, 3, 4, 5] my_list = numbers[:] print(my_list)

Back 162

[1, 2, 3, 4, 5]

Hint 162

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 163

What will the following code display? numbers = [1, 2, 3, 4, 5] my_list = numbers[-3:] print(my_list)

Back 163

[3, 4, 5]

Hint 163

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 164

What will the following code display? names = ['Jim', 'Jill', 'John', 'Jasmine'] if 'Jasmine' not in names: print('Cannot find Jasmine.') else: print("Jasmine's family:") print(names)

Back 164

Jasmine's family: ['Jim', 'Jill', 'John', 'Jasmine']

Hint 164

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 165

What is the difference between calling a list’s remove method and using the del statement to remove an element?

Back 165

The remove method searches for and removes an element containing a specific value. The del statement removes an element at a specific index.

Hint 165

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 166

How do you find the lowest and highest values in a list?

Back 166

You can use the built-in min and max functions.

Hint 166

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 167

Assume the following statement appears in a program: names = [] Which of the following statements would you use to add the string ‘Wendy’ to the list at index 0? Why would you select this statement instead of the other? a. names[0] = 'Wendy' b. names.append('Wendy')

Back 167

You would use statement b, names.append( ' Wendy ' ) . This is because element 0 does not exist. If you try to use statement a, an error will occur.

Hint 167

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 168

Describe the following list methods: a. index b. insert c. sort d. reverse

Back 168

a) The index method searches for an item in the list and returns the index of the first element containing that item. b) The insert method inserts an item into the list at a specified index. c) The sort method sorts the items in the list to appear in ascending order. d) The reverse method reverses the order of the items in the list.

Hint 168

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 169

Look at the following interactive session, in which a two-dimensional list is created. How many rows and how many columns are in the list? numbers = [[1, 2], [10, 20], [100, 200], [1000, 2000]]

Back 169

The list contains 4 rows and 2 columns.

Hint 169

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 170

Write a statement that creates a two-dimensional list with three rows and four columns. Each element should be assigned the value 0.

Back 170

mylist = [[0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0]]

Hint 170

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 171

Write a set of nested loops that display the contents of the numbers list shown in Checkpoint question 7.19.

Back 171

for r in range(4): for c in range(2): print(numbers[r][c])

Hint 171

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 172

What is the primary difference between a list and a tuple?

Back 172

The primary difference between tuples and lists is that tuples are immutable. That means that once a tuple is created, it cannot be changed.

Hint 172

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 173

Give two reasons why tuples exist.

Back 173

Here are three reasons: • Processing a tuple is faster than processing a list, so tuples are good choices when you are processing lots of data and that data will not be modified. • Tuples are safe. Because you are not allowed to change the contents of a tuple, you can store data in one and rest assured that it will not be modified (accidentally or otherwise) by any code in your program. • There are certain operations in Python that require the use of a tuple.

Hint 173

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 174

Assume that my_list references a list. Write a statement that converts it to a tuple.

Back 174

my_tuple = tuple(my_list)

Hint 174

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 175

Assume that my_tuple references a tuple. Write a statement that converts it to a list

Back 175

my_list = list(my_tuple)

Hint 175

Ch7 List Slicing, p.299The Lottery Number Generator Problem, p.334

Front 176

Assume the variable name references a string. Write a for loop that prints each character in the string.

Back 176

for letter in name: print(letter)

Hint 176

Ch8 The Vowels and Consonants Problem, p.367

Front 177

What is the index of the first character in a string?

Back 177

0

Hint 177

Ch8 The Vowels and Consonants Problem, p.368

Front 178

If a string has 10 characters, what is the index of the last character?

Back 178

9

Hint 178

Ch8 The Vowels and Consonants Problem, p.369

Front 179

What happens if you try to use an invalid index to access a character in a string?

Back 179

An IndexError exception will occur if you try to use an index that is out of range for a particular string.

Hint 179

Ch8 The Vowels and Consonants Problem, p.370

Front 180

How do you find the length of a string?

Back 180

Use the built-in len function.

Hint 180

Ch8 The Vowels and Consonants Problem, p.371

Front 181

What is wrong with the following code? animal = 'Tiger' animal[0] = 'L'

Back 181

The second statement attempts to assign a value to an individual character in the string. Strings are immutable, however, so the expression animal[0] cannot appear on the left side of an assignment operator.

Hint 181

Ch8 The Vowels and Consonants Problem, p.372

Front 182

What will the following code display? mystring = 'abcdefg' print(mystring[2:5])

Back 182

cde

Hint 182

Ch8 The Vowels and Consonants Problem, p.373

Front 183

What will the following code display? mystring = 'abcdefg' print(mystring[3:])

Back 183

defg

Hint 183

Ch8 The Vowels and Consonants Problem, p.374

Front 184

What will the following code display? mystring = 'abcdefg' print(mystring[:3])

Back 184

abc

Hint 184

Ch8 The Vowels and Consonants Problem, p.375

Front 185

What will the following code display? mystring = 'abcdefg' print(mystring[:])

Back 185

abcdefg

Hint 185

Ch8 The Vowels and Consonants Problem, p.376

Front 186

Write code using the in operator that determines whether 'd' is in mystring.

Back 186

if 'd' in mystring: print('Yes, it is there.')

Hint 186

Ch8 The Vowels and Consonants Problem, p.377

Front 187

Assume the variable big references a string. Write a statement that converts the string it references to lowercase, and assigns the converted string to the variable little.

Back 187

little = big.upper()

Hint 187

Ch8 The Vowels and Consonants Problem, p.378

Front 188

Write an if statement that displays “Digit” if the string referenced by the variable ch contains a numeric digit. Otherwise, it should display “No digit.”

Back 188

if ch.isdigit(): print('Digit') else: print('No digit')

Hint 188

Ch8 The Vowels and Consonants Problem, p.379

Front 189

What is the output of the following code? ch = 'a' ch2 = ch.upper() print(ch, ch2)

Back 189

a A

Hint 189

Ch8 The Vowels and Consonants Problem, p.380

Front 190

Write a loop that asks the user “Do you want to repeat the program or quit? (R/Q)”. The loop should repeat until the user has entered an R or Q (either uppercase or lowercase).

Back 190

again = input('Do you want to repeat ' + \ 'the program or quit? (R/Q) ') while again.upper() != 'R' and again.upper() != 'Q': again = input('Do you want to repeat the ' + 'program or quit? (R/Q) ')

Hint 190

Ch8 The Vowels and Consonants Problem, p.381

Front 191

What will the following code display? var = '$' print(var.upper())

Back 191

$

Hint 191

Ch8 The Vowels and Consonants Problem, p.382

Front 192

Write a loop that counts the number of uppercase characters that appear in the string referenced by the variable mystring.

Back 192

for letter in mystring: if letter.isupper(): count += 1

Hint 192

Ch8 The Vowels and Consonants Problem, p.383

Front 193

Assume the following statement appears in a program: days = 'Monday Tuesday Wednesday' Write a statement that splits the string, creating the following list: ['Monday', 'Tuesday', 'Wednesday']

Back 193

my_list = days.split()

Hint 193

Ch8 The Vowels and Consonants Problem, p.384

Front 194

Assume the following statement appears in a program: values = 'one$two$three$four' Write a statement that splits the string, creating the following list: ['one', 'two', 'three', 'four']

Back 194

my_list = values.split('$')

Hint 194

Ch8 The Vowels and Consonants Problem, p.385

Front 195

An element in a dictionary has two parts. What are they called?

Back 195

Key and value

Hint 195

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 196

Which part of a dictionary element must be immutable?

Back 196

The key

Hint 196

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 197

Suppose 'start' : 1472 is an element in a dictionary. What is the key? What is the value?

Back 197

The string ' start ' is the key, and the integer 1472 is the value.

Hint 197

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 198

Suppose a dictionary named employee has been created. What does the following statement do? employee['id'] = 54321

Back 198

It stores the key-value pair 'id' : 54321 in the employee dictionary.

Hint 198

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 199

What will the following code display? stuff = {1 : 'aaa', 2 : 'bbb', 3 : 'ccc'} print(stuff[3])

Back 199

ccc

Hint 199

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 200

How can you determine whether a key-value pair exists in a dictionary?

Back 200

You can use the in operator to test for a specific key.

Hint 200

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 201

Suppose a dictionary named inventory exists. What does the following statement do? del inventory[654]

Back 201

It deletes the element that has the key 654.

Hint 201

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 202

What will the following code display?stuff = {1: 'aaa', 2: 'bbb', 3: 'ccc'}print(len(stuff))

Back 202

3

Hint 202

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 203

What will the following code display?stuff = {1: 'aaa', 2: 'bbb', 3: 'ccc'}for k in stuff: print(k)

Back 203

123

Hint 203

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 204

What is the difference between the dictionary methods pop and popitem?

Back 204

The pop method accepts a key as an argument, returns the value that is associated with that key, and removes that key-value pair from the dictionary. The popitem method returns a randomly selected key-value pair, as a tuple, and removes that key-value pair from the dictionary.

Hint 204

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 205

What does the items method return?

Back 205

It returns all a dictionary’s keys and their associated values as a sequence of tuples.

Hint 205

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 206

What does the keys method return?

Back 206

It returns all the keys in a dictionary as a sequence of tuples.

Hint 206

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 207

What does the values method return?

Back 207

It returns all the values in the dictionary as a sequence of tuples.

Hint 207

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 208

Are the elements of a set ordered or unordered?

Back 208

Unordered

Hint 208

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 209

Does a set allow you to store duplicate elements?

Back 209

No

Hint 209

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 210

How do you create an empty set?

Back 210

You call the built-in set function.

Hint 210

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 211

After the following statement executes, what elements will be stored in the myset set? myset = set('Jupiter')

Back 211

The set will contain these elements (in no particular order): 'J' , 'u' , 'p' , 'i' , 't' , 'e' , and 'r' .

Hint 211

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 212

After the following statement executes, what elements will be stored in the myset set? myset = set(25)

Back 212

The set will contain one element: 25.

Hint 212

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 213

After the following statement executes, what elements will be stored in the myset set? myset = set('www xxx yyy zzz')

Back 213

The set will contain these elements (in no particular order): 'w' , ' ' , 'x' , 'y' , and 'z' .

Hint 213

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 214

After the following statement executes, what elements will be stored in the myset set? myset = set([1, 2, 2, 3, 4, 4, 4])

Back 214

The set will contain these elements (in no particular order): 1, 2, 3, and 4.

Hint 214

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 215

After the following statement executes, what elements will be stored in the myset set? myset = set(['www', 'xxx', 'yyy', 'zzz'])

Back 215

The set will contain these elements (in no particular order): 'www' , 'xxx' , 'yyy' , and 'zzz' .

Hint 215

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 216

How do you determine the number of elements in a set?

Back 216

You pass the set as an argument to the len function.

Hint 216

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 217

After the following statement executes, what elements will be stored in the myset set? myset = set([10, 9, 8]) myset.update([1, 2, 3])

Back 217

The set will contain these elements (in no particular order): 10, 9, 8, 1, 2, and 3.

Hint 217

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 218

After the following statement executes, what elements will be stored in the myset set? myset = set([10, 9, 8]) myset.update('abc')

Back 218

The set will contain these elements (in no particular order): 10, 9, 8, 'a' , 'b' , and 'c' .

Hint 218

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 219

What is the difference between the remove and discard methods?

Back 219

If the specified element to delete is not in the set, the remove method raises a KeyError exception, but the discard method does not raise an exception.

Hint 219

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 220

How can you determine whether a specific element exists in a set?

Back 220

You can use the in operator to test for the element.

Hint 220

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 221

After the following code executes, what elements will be members of set3? set1 = set([10, 20, 30]) set2 = set([100, 200, 300]) set3 = set1.union(set2)

Back 221

{10, 20, 30, 100, 200, 300}

Hint 221

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 222

After the following code executes, what elements will be members of set3? set1 = set([1, 2, 3, 4]) set2 = set([3, 4, 5, 6]) set3 = set1.intersection(set2)

Back 222

{3, 4}

Hint 222

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 223

After the following code executes, what elements will be members of set3? set1 = set([1, 2, 3, 4]) set2 = set([3, 4, 5, 6]) set3 = set1.difference(set2)

Back 223

{1, 2}

Hint 223

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 224

After the following code executes, what elements will be members of set3? set1 = set([1, 2, 3, 4]) set2 = set([3, 4, 5, 6]) set3 = set2.difference(set1)

Back 224

{5, 6}

Hint 224

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 225

After the following code executes, what elements will be members of set3? set1 = set(['a', 'b', 'c']) set2 = set(['b', 'c', 'd']) set3 = set1.symmetric_difference(set2)

Back 225

{'a', 'd'}

Hint 225

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 226

Look at the following code: set1 = set([1, 2, 3, 4]) set2 = set([2, 3]) Which of the sets is a subset of the other? Which of the sets is a superset of the other?

Back 226

set2 is a subset of set1 , and set1 is a superset of set2 .

Hint 226

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 227

What is object serialization?

Back 227

The process of converting the object to a stream of bytes that can be saved to file for later retrieval.

Hint 227

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 228

When you open a file for the purpose of saving a pickled object to it, what file access mode do you use?

Back 228

wb'

Hint 228

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 229

When you open a file for the purpose of retrieving a pickled object from it, what file access mode do you use?

Back 229

rb'

Hint 229

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 230

What module do you import if you want to pickle objects?

Back 230

The pickle module

Hint 230

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 231

What function do you call to pickle an object?

Back 231

pickle.dump

Hint 231

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 232

What function do you call to retrieve and unpickle an object?

Back 232

pickle.load

Hint 232

Ch9 Introduction to Dictionaries, p.369Introduction to Sets,p.392The CapitalQuiz Problem, p.416

Front 233

What is an object?

Back 233

An object is a software entity that contains both data and procedures.

Hint 233

Ch10 Classes and Objects, p.423The Pet class, p.476

Front 234

What is encapsulation?

Back 234

Encapsulation is the combining of data and code into a single object.

Hint 234

Ch10 Classes and Objects, p.423The Pet class, p.476

Front 235

Why is an object’s internal data usually hidden from outside code?

Back 235

When an object’s internal data is hidden from outside code and access to that data is restricted to the object’s methods, the data is protected from accidental corruption. In addition, the programming code outside the object does not need to know about the format or internal structure of the object’s data.

Hint 235

Ch10 Classes and Objects, p.423The Pet class, p.476

Front 236

What are public methods? What are private methods?

Back 236

Public methods can be accessed by entities outside the object. Private methods cannot be accessed by entities outside the object. They are designed to be accessed internally.

Hint 236

Ch10 Classes and Objects, p.423The Pet class, p.476

Front 237

You hear someone make the following comment: “A blueprint is a design for a house. A carpenter can use the blueprint to build the house. If the carpenter wishes, he or she can build several identical houses from the same blueprint.” Think of this as a metaphor for classes and objects. Does the blueprint represent a class, or does it represent an object?

Back 237

The metaphor of a blueprint represents a class.

Hint 237

Ch10 Classes and Objects, p.423The Pet class, p.476

Front 238

In this chapter, we use the metaphor of a cookie cutter and cookies that are made from the cookie cutter to describe classes and objects. In this metaphor, are objects the cookie cutter, or the cookies?

Back 238

Objects are the cookies.

Hint 238

Ch10 Classes and Objects, p.423The Pet class, p.476

Front 239

What is the purpose of the _ _init_ _ method? When does it execute?

Back 239

Its purpose is to initialize an object’s data attributes. It executes immediately after the object is created.

Hint 239

Ch10 Classes and Objects, p.423The Pet class, p.476

Front 240

What is the purpose of the self parameter in a method?

Back 240

When a method executes, it must have a way of knowing which object’s data attributes it is supposed to operate on. That’s where the self parameter comes in. When a method is called, Python automatically makes its self parameter reference the specific object that the method is supposed to operate on.

Hint 240

Ch10 Classes and Objects, p.423The Pet class, p.476

Front 241

In a Python class, how do you hide an attribute from code outside the class?

Back 241

By starting the attribute’s name with two underscores

Hint 241

Ch10 Classes and Objects, p.423The Pet class, p.476

Front 242

What is the purpose of the __str__ method?

Back 242

It returns a string representation of the object.

Hint 242

Ch10 Classes and Objects, p.423The Pet class, p.476

Front 243

How do you call the _ _str_ _ method?

Back 243

By passing the object to the built-in str method

Hint 243

Ch10 Classes and Objects, p.423The Pet class, p.476

Front 244

What is an instance attribute?

Back 244

An attribute that belongs to a specific instance of a class

Hint 244

Ch10 Classes and Objects, p.423The Pet class, p.476

Front 245

A program creates 10 instances of the Coin class. How many __sideup attributes exist in memory?

Back 245

10

Hint 245

Ch10 Classes and Objects, p.423The Pet class, p.476

Front 246

What is an accessor method? What is a mutator method?

Back 246

A method that returns a value from a class’s attribute but does not change it is known as an accessor method. A method that stores a value in a data attribute or changes the value of a data attribute in some other way is known as a mutator method.

Hint 246

Ch10 Classes and Objects, p.423The Pet class, p.476

Front 247

The typical UML diagram for a class has three sections. What appears in these three sections?

Back 247

The top section is where you write the name of the class. The middle section holds a list of the class’s fields. The bottom section holds a list of the class’s methods.

Hint 247

Ch10 Classes and Objects, p.423The Pet class, p.476

Front 248

What is a problem domain?

Back 248

A written description of the real-world objects, parties, and major events related to the problem

Hint 248

Ch10 Classes and Objects, p.423The Pet class, p.476

Front 249

When designing an object-oriented application, who should write a description of the problem domain?

Back 249

If you adequately understand the nature of the problem you are trying to solve, you can write a description of the problem domain yourself. If you do not thoroughly understand the nature of the problem, you should have an expert write the description for you.

Hint 249

Ch10 Classes and Objects, p.423The Pet class, p.476

Front 250

How do you identify the potential classes in a problem domain description?

Back 250

First, identify the nouns, pronouns, and pronoun phrases in the problem domain description. Then, refine the list to eliminate duplicates, items that you do not need to be concerned with in the problem, items that represent objects instead of classes, and items that represent simple values that can be stored in variables.

Hint 250

Ch10 Classes and Objects, p.423The Pet class, p.476

Front 251

What are a class’s responsibilities?

Back 251

The things that the class is responsible for knowing and the actions that the class is responsible for doing

Hint 251

Ch10 Classes and Objects, p.423The Pet class, p.476

Front 252

What two questions should you ask to determine a class’s responsibilities?

Back 252

In the context of this problem, what must the class know? What must the class do?

Hint 252

Ch10 Classes and Objects, p.423The Pet class, p.476

Front 253

Will all of a classes actions always be directly mentioned in the problem domain description?

Back 253

No, not always

Hint 253

Ch10 Classes and Objects, p.423The Pet class, p.476

Front 254

In this section we discussed superclasses and subclasses. Which is the general class and which is the specialized class?

Back 254

A superclass is a general class, and a subclass is a specialized class.

Hint 254

Ch11 The Person and Customer Classes, p.505

Front 255

What does it mean to say there is an “is a” relationship between two objects?

Back 255

When one object is a specialized version of another object, there is an “is a” relationship between them. The specialized object “is a” version of the general object.

Hint 255

Ch11 The Person and Customer Classes, p.506

Front 256

What does a subclass inherit from its superclass?

Back 256

It inherits all the superclass’s attributes.

Hint 256

Ch11 The Person and Customer Classes, p.507

Front 257

Look at the following code, which is the first line of a class definition. What is the name of the superclass? What is the name of the subclass? class Canary(Bird):

Back 257

Bird is the superclass, and Canary is the subclass.

Hint 257

Ch11 The Person and Customer Classes, p.508

Front 258

Look at the following class definitions: class Vegetable: def _ _init_ _(self, vegtype): self._ _vegtype = vegtype def message(self): print("I'm a vegetable.") class Potato(Vegetable): def _ _init_ _(self): Vegetable._ _init_ _(self, 'potato') def message(self): print("I'm a potato.") Given these class definitions, what will the following statements display? v = Vegetable('veggie') p = Potato() v.message() p.message()

Back 258

I’m a vegetable. I’m a potato.

Hint 258

Ch11 The Person and Customer Classes, p.509

Front 259

It is said that a recursive algorithm has more overhead than an iterative algorithm. What does this mean?

Back 259

A recursive algorithm requires multiple method calls. Each method call requires several actions to be performed by the JVM. These actions include allocating memory for parameters and local variables and storing the address of the program location where control returns after the method terminates. All these actions are known as overhead. In an iterative algorithm, which uses a loop, such overhead is unnecessary.

Hint 259

Ch12 The Recursive Multiplication Problem, p.524

Front 260

What is a base case?

Back 260

A case in which the problem can be solved without recursion

Hint 260

Ch12 The Recursive Multiplication Problem, p.525

Front 261

What is a recursive case?

Back 261

Cases in which the problem is solved using recursion

Hint 261

Ch12 The Recursive Multiplication Problem, p.526

Front 262

What causes a recursive algorithm to stop calling itself?

Back 262

When it reaches the base case

Hint 262

Ch12 The Recursive Multiplication Problem, p.527

Front 263

What is direct recursion? What is indirect recursion?

Back 263

In direct recursion, a recursive method calls itself. In indirect recursion, method A calls method B, which in turn calls method A.

Hint 263

Ch12 The Recursive Multiplication Problem, p.528

Front 264

What is a user interface?

Back 264

The part of a computer and its operating system with which the user interacts

Hint 264

Ch13 Creating a simple GUI Application, p.532Responding to Button Clicks, p.538The Name and Address Problem, p.562

Front 265

How does a command line interface work?

Back 265

A command line interface typically displays a prompt, and the user types a command, which is then executed.

Hint 265

Ch13 Creating a simple GUI Application, p.532Responding to Button Clicks, p.538The Name and Address Problem, p.562

Front 266

When the user runs a program in a text-based environment, such as the command line, what determines the order in which things happen?

Back 266

The program

Hint 266

Ch13 Creating a simple GUI Application, p.532Responding to Button Clicks, p.538The Name and Address Problem, p.562

Front 267

What is an event-driven program?

Back 267

A program that responds to events that take place, such as the user clicking a button

Hint 267

Ch13 Creating a simple GUI Application, p.532Responding to Button Clicks, p.538The Name and Address Problem, p.562

Front 268

Briefly describe each of the following tkinter widgets: a) Label b) Entry c) Button d) Frame

Back 268

a) Label—An area that displays one line of text or an image b) Entry—An area in which the user may type a single line of input from the keyboard c) Button—A button that can cause an action to occur when it is clicked d) Frame—A container that can hold other widgets

Hint 268

Ch13 Creating a simple GUI Application, p.532Responding to Button Clicks, p.538The Name and Address Problem, p.562

Front 269

How do you create a root widget?

Back 269

You create an instance of the tkinter module’s Tk class.

Hint 269

Ch13 Creating a simple GUI Application, p.532Responding to Button Clicks, p.538The Name and Address Problem, p.562

Front 270

What does the tkinter module’s mainloop function do?

Back 270

This function runs like an infinite loop until you close the main window.

Hint 270

Ch13 Creating a simple GUI Application, p.532Responding to Button Clicks, p.538The Name and Address Problem, p.562

Front 271

What does a widget’s pack method do?

Back 271

The pack method arranges a widget in its proper position, and it makes the widget visible when the main window is displayed.

Hint 271

Ch13 Creating a simple GUI Application, p.532Responding to Button Clicks, p.538The Name and Address Problem, p.562

Front 272

If you create two Label widgets and call their pack methods with no arguments, how will the Label widgets be arranged inside their parent widget?

Back 272

One will be stacked on top of the other.

Hint 272

Ch13 Creating a simple GUI Application, p.532Responding to Button Clicks, p.538The Name and Address Problem, p.562

Front 273

What argument would you pass to a widget’s pack method to specify that it should be positioned as far left as possible inside the parent widget?

Back 273

side=–left—

Hint 273

Ch13 Creating a simple GUI Application, p.532Responding to Button Clicks, p.538The Name and Address Problem, p.562

Front 274

How do you retrieve data from an Entry widget?

Back 274

You use an Entry widget’s get method to retrieve the data that the user has typed into the widget.

Hint 274

Ch13 Creating a simple GUI Application, p.532Responding to Button Clicks, p.538The Name and Address Problem, p.562

Front 275

When you retrieve a value from an Entry widget, of what data type is it?

Back 275

It is a string.

Hint 275

Ch13 Creating a simple GUI Application, p.532Responding to Button Clicks, p.538The Name and Address Problem, p.562

Front 276

What module is the StringVar class in?

Back 276

tkinter

Hint 276

Ch13 Creating a simple GUI Application, p.532Responding to Button Clicks, p.538The Name and Address Problem, p.562

Front 277

What can you accomplish by associating a StringVar object with a Label widget?

Back 277

Any value that is stored in the StringVar object will automatically be displayed in the Label widget.

Hint 277

Ch13 Creating a simple GUI Application, p.532Responding to Button Clicks, p.538The Name and Address Problem, p.562

Front 278

You want the user to be able to select only one item from a group of items. Which type of component would you use for the items, radio buttons or check boxes?

Back 278

You would use radio buttons.

Hint 278

Ch13 Creating a simple GUI Application, p.532Responding to Button Clicks, p.538The Name and Address Problem, p.562

Front 279

You want the user to be able to select any number of items from a group of items. Which type of component would you use for the items, radio buttons or check boxes?

Back 279

You would use check buttons.

Hint 279

Ch13 Creating a simple GUI Application, p.532Responding to Button Clicks, p.538The Name and Address Problem, p.562

Front 280

How can you use an IntVar object to determine which Radiobutton has been selected in a group of Radiobuttons?

Back 280

When you create a group of Radiobuttons, you associate them all with the same IntVar object. You also assign a unique integer value to each Radiobutton widget. When one of the Radiobutton widgets is selected, it stores its unique integer value in the IntVar object.

Hint 280

Ch13 Creating a simple GUI Application, p.532Responding to Button Clicks, p.538The Name and Address Problem, p.562

Front 281

How can you use an IntVar object to determine whether a Checkbutton has been selected?

Back 281

You associate a different IntVar object with each Checkbutton. When a Checkbutton is selected, its associated IntVar object will hold the value 1. When a Checkbutton is deselected, its associated IntVar object will hold the value 0.

Hint 281

Ch13 Creating a simple GUI Application, p.532Responding to Button Clicks, p.538The Name and Address Problem, p.562