CPT 168 Final Review Flashcards by Nolan Kidd

The __________ software for a computer provides the software that’s needed for running applications.

systems

How well did you know this?

Not at all

Perfectly

The data in __________ is persistent so it is not lost when an application ends.

disk storage

How well did you know this?

Not at all

Perfectly

To create a Python program, you use:

IDLE’s editor

How well did you know this?

Not at all

Perfectly

The following is an example of \_\_\_\_\_\_\_\_\_\_.
print("Hello out there!")
# get input
name = input("Who are you?")
print("Goodbye, " , name)

source code

How well did you know this?

Not at all

Perfectly

A console application runs

via a command prompt

How well did you know this?

Not at all

Perfectly

The data in __________ is lost when an application ends.

main memory

How well did you know this?

Not at all

Perfectly

Python is considered a good first language to learn because:

all of the above

How well did you know this?

Not at all

Perfectly

A runtime error is also known as:

an exception

How well did you know this?

Not at all

Perfectly

When an exception occurs while a program is running,

the program crashes and an error message is displayed

How well did you know this?

Not at all

Perfectly

To run a Python program from IDLE, you use:

the F5 key

How well did you know this?

Not at all

Perfectly

The goal of __________ is to fix all the errors in a program.

debugging

How well did you know this?

Not at all

Perfectly

To test a Python statement, you use:

IDLE’s interactive shell

How well did you know this?

Not at all

Perfectly

Which of the following translates bytecode into instructions for the computer?

the Python virtual machine

How well did you know this?

Not at all

Perfectly

A web application runs

through a browser

How well did you know this?

Not at all

Perfectly

The following is an example of \_\_\_\_\_\_\_\_\_\_.
     #!/usr/bin/env python 3

a shebang line

How well did you know this?

Not at all

Perfectly

Which type of errors must be fixed before the program can be compiled?

syntax errors

How well did you know this?

Not at all

Perfectly

The goal of __________ is to find all the errors in a program.

testing

How well did you know this?

Not at all

Perfectly

Given that pi = 3.1415926535, which of the following print() functions displays:
pi = 3.14

print(“pi = “ + str(round(pi, 2)))

How well did you know this?

Not at all

Perfectly

Given: x = 23 , y = 15
What is the value of new_num after the following statement executes?
new_num = x % y

How well did you know this?

Not at all

Perfectly

Given: x = 23 , y = 15
What is the value of new_num after the following statement executes?
new_num = x // y

How well did you know this?

Not at all

Perfectly

Given: x = 7 , y = 2 , z = 1.5
What is the value of new_num after the following statement executes?
new_num = x / y + z

5.0

How well did you know this?

Not at all

Perfectly

Python comments

all of the above

How well did you know this?

Not at all

Perfectly

Python relies on correct __________ to determine the meaning of a statement.

indentation

How well did you know this?

Not at all

Perfectly

What is the argument of the print() function in the following Python statement?
print(“My student ID is “ + str(123456) )

“My student ID is “ + str(123456)

How well did you know this?

Not at all

Perfectly

What is the value of my_num after the following statement executes? my_num = (50 + 2 * 10 - 4) / 2

``` What is the value of my_num after the following statements execute? my_num = 5 my_num += 20 my_num -= 12 my_num *= 0.5 ```

6.5

What is the value of number after the following statement executes? number = (5 ** 2) * ((10 - 4) / 2)

What will be the result of the following code if the user enters 81 at the prompt? score_curve = 7 score = input("Enter your score on the exam: ") score_curve += score print(score_curve)

error: you cannot use the += operator to add a string variable to an int value

What will display after the following print() function is executed? print("Welcome!\nNow that you have learned about", "input\nand output, you may be wondering,\"What\nis", "next?\"")

Welcome! Now that you have learned about input and output, you may be wondering, "What is next?"

What will the following print() function display? | print("lions", "tigers", "bears", sep = ' & ', end = ' oh, my!!')

lions & tigers & bears oh, my!!

What, if anything, is wrong with this code? my_age = input("Enter your age: ") myNewAge = int(my_age) + 5 print("In 5 years you will be", myNewAge, ".")

nothing is wrong with this code

What, if anything, is wrong with this code? rating = input("Enter the rating for this product: ") rating = rating + 2 print("The adjusted rating is " + rating + ".")

a string variable is used in an arithmetic expression

What, if anything, is wrong with this code? student_score = int(input("Enter this student's score: ")) score = student_score + 5 print("With the 5-point curve, the student’s score is ", scores, ".")

an undeclared variable name is used in the print() function

Which of the following data types would you use to store the number 25.62?

float

Which of the following doesn’t follow the best naming practices for variables?

pRate

Which of the following variable names uses camel case?

firstName

Which of the following will get a floating-point number from the user?

my_number = float(input("Enter a number:"))

A for loop that uses a range() function is executed

once for each integer in the collection returned by the range() function

Code Example 3-1 ``` num_widgets = 0 while True: choice = input("Would you like to buy a widget? (y/n): ") if choice.lower() == "y": num_widgets += 1 else: break print("You bought", num_widgets , "widget(s)." ``` Refer to Code Example 3-1. If the user enters “Y” at the prompt, what does the program print to the console?

Would you like to buy a widget? (y/n):

Code Example 3-1 ``` num_widgets = 0 while True: choice = input("Would you like to buy a widget? (y/n): ") if choice.lower() == "y": num_widgets += 1 else: break print("You bought", num_widgets , "widget(s).") ``` Refer to Code Example 3-1. If the user enters “no” at the prompt, what does the program print to the console?

You bought 0 widget(s) today.

Code Example 3-1 ``` num_widgets = 0 while True: choice = input("Would you like to buy a widget? (y/n): ") if choice.lower() == "y": num_widgets += 1 else: break print("You bought", num_widgets , "widget(s).") ``` Refer to Code Example 3-1. Which of the following could be a pseudocode plan for the program?

``` Define widget count variable Begin infinite loop Get user input IF user buys widget add 1 to widget count ELSE end loop Display results ```

For the following code, what will the result be if the user enters 4 at the prompt? product = 1 end_value = int(input("Enter a number: ")) for i in range(1, end_value): product = product * i i += 1 print("The product is ", product)

The product is 6

For the following code, what will the result be if the user enters 4 at the prompt? product = 1 end_value = int(input("Enter a number: ")) for i in range(1, end_value+1): product = product * i i += 1 print("The product is ", product)

The product is 24

For the following code, what will the result be if the user enters 5 at the prompt? sum = 0 end_value = int(input("Enter a number: ")) for i in range(1, end_value): sum = sum + i print(sum, end=", ")

1, 3, 6, 10,

Given the following code, select the compound condition that makes sure that the input is an integer greater than 0 and less than 1,000. my_num = input("Enter a number between 1 and 999:") check_num = int(my_num) while _________________________: my_num = input("Try again. The number must be between 1 and 999") check_num = int(my_num)

check_num <= 0 or check_num >= 1000

How many times will “Hi again!” be displayed after the following code executes? for i in range(0, 12, 2): print("Hi, again!")

``` How many times will “Hi there!” be displayed after the following code executes? num = 2 while num < 12: print("Hi, there!") num += 2 ```

If you want to code an if clause, but you don’t want to perform any action, you can code

a pass statement

In a while loop, the Boolean expression is tested

before the loop is executed

Pseudocode can be used to plan

the coding of control structures

``` Python will sort the strings that follow in this sequence: Peach peach 1peach 10Peaches ```

10Peaches, 1peach, Peach, peach

The and operator has

higher precedence than the or operator, but lower precedence than the not operator

To compare two strings with mixed uppercase and lowercase letters, a programmer can first use the

lower() method to convert all characters in each string to lowercase.

To jump to the end of the current loop, you can use the

break statement

``` What will be displayed after the following code executes? guess = 19 if guess < 19: print("Too low") elif guess > 19: print("Too high") ```

nothing will display

``` What will be displayed after the following code is executed? counter = 1 while counter <= 20: print(counter, end=" ") counter *= 3 print("\nThe loop has ended.") ```

1 3 9 | The loop has ended.

``` What will the output of the following code be if the user enters 3 at the prompt? your_num = int(input("Enter a number:")) while (your_num > 0): product = your_num * 5 print(your_num, " * 5 = ", product) your_num -= 1 ```

3 * 5 = 15 2 * 5 = 10 1 * 5 = 5

``` What will this loop display? sum = 0 for i in range(0, 25, 5): sum += i print(sum) ```

When two strings are compared, they are evaluated based on the ___________________ of the characters in the string.

sort sequence

Which of the following begins by testing a condition defined by a Boolean expression and then executes a block of statements if the condition is true?

a while statement

Which of the following can use the range() function to loop through a block of statements?

a for statement

Which of the following creates a Boolean variable?

flag = True

Which of the following in this expression is evaluated first? age >= 65 and status == "retired" or age < 18

age >= 65

Which of the following in this expression is evaluated first? age >= 65 or age <= 18 or status == "retired"

age >= 65

Which of the following is not an acceptable way to code a nested structure?

nest an else clause within an elif clause

Which of the following is true for an if statement that has both elif and else clauses?

If the condition in the if clause is true, the statements in that clause are executed.

Which type of expression has a value of either true or false?

Boolean

Which of the following is not true of hierarchy charts?

Related functions should be combined into a single function.

A file that contains reusable code is called a

module

A global variable

is defined outside of all functions

A local variable is defined

inside a function

A return statement

can be used to return a local variable to the calling function

Assuming the random module has been imported into its default namespace, which of the following could possibly result in a value of 0.94?

number = random.random()

Assuming the random module has been imported into its default namespace, which of the following could be used to simulate a coin toss where 0 = heads and 1 = tails?

number = random.randint(0, 1)

Assuming the random module has been imported into its default namespace, which of the following could be used to generate a random even integer from 2 through 200?

number = random.randrange(2, 202, 2)

Before you can use a standard module like the random module, you need to

import the module

``` Code Example 4-1 def get_username(first, last): s = first + "." + last return s.lower() ``` ``` def main(): first_name = input("Enter your first name: ") last_name = input("Enter your last name: ") username = get_username(first_name, last_name) print("Your username is: " + username) ``` if __name__ == "__main__": main() Refer to Code Example 4-1: What function is called first when the program runs?

main()

first, last

``` Code Example 4-1 def get_username(first, last): s = first + "." + last return s.lower() ``` ``` def main(): first_name = input("Enter your first name: ") last_name = input("Enter your last name: ") username = get_username(first_name, last_name) print("Your username is: " + username) ``` if __name__ == "__main__": main() Refer to Code Example 4-1: If the user enters ‘Lopez’ for the first prompt in main() and ‘Maria’ for the second prompt, what will display?

lopez.maria

local

``` Code Example 4-2 def get_volume(width, height, length=2): volume = width * height * length return volume ``` ``` def main(): l = 3 w = 4 h = 5 v = get_volume(l, w, h) print(v) ``` if __name__ == "__main__": main() Refer to Code Example 4-2: When this program runs, what does it print to the console?

``` Code Example 4-2 def get_volume(width, height, length=2): volume = width * height * length return volume ``` ``` def main(): l = 3 w = 4 h = 5 v = get_volume(l, w, h) print(v) ``` if __name__ == "__main__": main() Refer to Code Example 4-2: If you add the following code to the end of the main() method, what does it print to the console? print(get_volume(10, 2))

Code Example 4-3 main program: import arithmetic as a ``` def main(): num1 = 5 num2 = 6 result = a.add(num1, num2) print("The sum is", result) ``` if __name__ == "__main__": main() ``` arithmetic module: def add(x = 4, y = 2): z = x + y return z ``` Refer to Code Example 4-3: What will be displayed after the code runs?

The sum is 11

5, 6

Code Example 4-4 main program: import arithmetic as a ``` def multiply(num1, num2): product = num1 * num2 result = a.add(product, product) return result ``` ``` def main(): num1 = 4 num2 = 3 answer = multiply(num1, num2) print("The answer is", answer) ``` if __name__ == "__main__": main() ``` arithmetic module: def add(x, y): z = x + y return z ``` Refer to Code Example 4-4: What values are in x and y after the code runs?

12, 12

the multiply() function

The answer is 24

If you import two modules into the global namespace and each has a function named get_value(),

a name collision occurs

The best way to call the main() function of a program is to code

an if statement that calls the main() function only if the current module is the main module

The default namespace for a module is

the same as the name of the module

To assign a default value to an argument when you define a function, you

code the name of the argument, the assignment operator (=), and the default value

To call a function with named arguments, you code the

name of each argument, an equals sign, and the value or variable that’s being passed

To call a function, you code the function name and

a set of parentheses that contains zero or more arguments

To define a function, you code the def keyword and the name of the function followed by

a set of parentheses that contains zero or more arguments

Which of the following statements imports a module into the default namespace?

import temperature

Which of the following statements imports a module into the global namespace?

from temperature import *

Which of the following statements is not true about the documentation of a module?

You can use regular Python comments to document the functions of the module.

``` Which statement would you use to call the print_name() function from a module named address that has been imported with this statement? import address as a ```

a.print_name(name)

``` A programmer created this code for a client: def divide(numerator, denominator): quotient = numerator / denominator return quotient ``` ``` def main(): numerator = int(input("Enter the numerator: ")) denominator = int(input("Enter the denominator: ")) quotient = divide(numerator, denominator) print("The quotient is ", quotient) ``` ``` if __name__ == "__main__": main() The programmer tested this code with the following three sets of data: 1. numerator = 9, denominator = 3 2. numerator = -50, denominator = 5 3. numerator = 389, denominator = -26 The results were: 1. The quotient is 3.0 2. The quotient is -10.0 3. The quotient is -14.961538461538462 However, once the program was in use, the client reported that sometimes the program crashed. Can you explain why? ```

Programmer didn’t test for a 0 value in the denominator.

Code Example 5-1 1. count = 1 2. item_total = 0 3. item = 0 4. while count < 4: 5. item = int(input("Enter item cost: ")) 6. item_total += item 7. count += 1 8. average_cost = round(item_total / count) 9. print("Total cost:", item_total, "\nAverage cost:", average_cost) Refer to Code Example 5-1: If the user enters 5, 10, and 15 at the prompts, the output is: Total cost: 30 Average cost: 8 Which line should be changed to fix this logic error?

change line 8 to: average_cost = round(item_total / (count - 1))

Code Example 5-2 1. # This application displays a student's score after a 5-point curve 2. 3. def display_info(fname, lname, score): 4. print("Hello, " , fname, " " , Lname) 5. print("Your score on this exam is ", score) 6. score = score + 5 7. 8. def main(): 9. first = input("first name: ") 10. last = input("last name: ") 11. grade = input("exam score: ") 12. display_info(last, first, score) 13. 14. # if started as the main module, call the main function 15. if __name__ == "__main__": 16. main() Refer to Code Example 5-2: What is the error in the main() function?

The input statement on line 11 gets a variable named grade but sends in an undefined variable named score on line 12

The variable Lname on line 4 does not exist

The variable score has been input as a string so it must be converted to an int or float.

The curve is calculated after the score has been displayed.

Given the following code and its output: 1. discount_rate = .1 2. item = 89.95 3. discount = item * discount_rate 4. print("The discount on this item is $", discount)) Output: The discount on this item is $ 8.995000000000001 Which of the following would produce a user-friendly correct result?

change line 4 to: print("The discount on this item is $", round(discount, 2))

Given the following code, if the user worked 45 hours at $10.00/hour, the output is as shown below. 1. def main(): 2. hours = float(input("How many hours did you work? ")) 3. rate = float(input("What is your hourly rate? ")) 4. if (hours > 40) and (rate < 15): 5. pay = (hours * rate) + (hours - 40 * rate * 1.5) 6. else: 7. pay = hours * rate 8. print("Your pay is: $ ", round(pay, 2)) Output: Your pay is: $ -105.0 Which line should be changed to fix this logic error?

change line 5 to: pay = (40 * rate) + ((hours - 40) * rate * 1.5)

The stack is available when an exception occurs. It displays a list of

just the functions that were called prior to the exception

To test the functions of a module from the IDLE shell, you

import the module and then call any function from the IDLE shell

What line number of the following code contains an error and what type of error is it? 1. def sales_tax(amt) 2. sale = amt + (amt * .06) 3. return sale 4. 5. def main(): 6. print("Welcome to the 6% tax calculator!\n") 7. total = int(input("Please enter the total amount: ")) 8. print("The total amount after tax is: ", sales_tax(total))

line 1, syntax error

What line number of the following code contains an error and what type of error is it? 1. count = 1 2. while count <= 4: 3. print(count, end=" ") 4. i *= 1 5. print("\nThe loop has ended.")

line 4, runtime error

When the IDLE debugger reaches a breakpoint, you can do all but one of the following. Which one is it?

view the values of all the variables that you’ve stepped through

When you plan the test runs for a program, you should do all but one of the following. Which one is it?

list the expected exceptions for each test run

When you trace the execution of a program, you insert print() functions at key points in the program. It makes sense for these functions to do all but one of the following. Which one is it?

display the values of the global constants used by the function

When you use the IDLE debugger, you start by setting a breakpoint

on a statement before the statement you think is causing the bug

Which of the following is not a common type of syntax error?

invalid variable names

Which of the following is not true about top-down coding and testing?

You should always start by coding and testing the most difficult functions.

Which type of error prevents a program from compiling and running?

syntax

Which type of error throws an exception that stops execution of the program?

runtime

``` Code Example 6-1 def main(): students = [["Lizzy", 73, "C"], ["Mike", 98, "A"], ["Joel", 88, "B+"], ["Anne", 93, "A"]] ``` for student in students: for item in student: print(item, end=" ") if __name__ == "__main__": main() Refer to Code Example 6-1: What is in the second row of the students list?

"Mike", 98, "A"

The __________ method adds an item to the end of a list.

append()

Given the following code, what would be displayed after the code executes? def main(): furry_pets = ["dog", "cat", "ferret", "hamster", "bunny"] feathered_pets = ["canary", "parrot", "budgie", "hawk"] all_pets = furry_pets + feathered_pets new_pets =[] i = 0 for item in all_pets: if item[i][0] == "c": new_pets.append(item) print("The pet store sells:", all_pets) print("These start with the letter c:", new_pets)

The pet store sells: ['dog', 'cat', 'ferret', 'hamster', 'bunny', 'canary', 'parrot', 'budgie', 'hawk'] These start with the letter c: ['cat', 'canary']

Which of the following is not true about a list of lists?

To delete an item in the outer list, you first have to delete the list in the item.

Given the tuple that follows, which of the following assigns the values in the tuple to variables? numbers = (22, 33, 44, 55)

w, x, y, z = numbers

When you use a multiple assignment statement to unpack a tuple,

you assign the tuple to a two or more variable names separated by commas

Given the following code, what is the value of my_name and what does the list consist of after the second statement is executed? names = ["Lizzy", "Mike", "Joel", "Anne", "Donny"] my_name = name.pop()

my_name = "Donny", names = ["Lizzy", "Mike", "Joel", "Anne"]

To remove the item “mangos” from the following list, you would use which of these methods? fruit = ["apple", "banana", "grapes", "mangos", "oranges"]

fruit.remove("mangos") or fruit.pop(3)

When a function changes the data in a list, the changed list

does not need to be returned because lists are mutable.

Which of the following statements about list copies is not true? When you make a

deep copy of a list, both variables refer to the same list.

What would be displayed after the following code snippet executes? costumes = ["ghost", "witch", "elf", "ogre"] name = "elf" if name in costumes: costumes.remove(name) for item in costumes: print(item)

ghost witch ogre

What will display after the following code executes? def add_item(list, food): food = "apple pie" list.append(food) ``` def main(): lunch = ["sandwich", "chips", "pickle"] food = "banana" add_item(lunch, food) print(lunch) ``` main()

['sandwich', 'chips', 'pickle', 'apple pie']

Given the following code, what would the list consist of after the second statement? ages = [22, 35, 24, 17, 28] ages.insert(3, 4)

ages = [22, 35, 24, 4, 17, 28]

Which of the following creates a tuple of six strings?

vehicles = ("sedan","SUV","motorcycle","bicycle","hatchback","truck")

Which of the following functions randomly selects one item in a list?

choice()

Given the following list, what is the value of ages[5]? | ages = [22, 35, 24, 17, 28]

None: Index error

[['Mike',98,'A'],['Lizzy',73,'C'],['Joel',88,'B+'],['Anne',93,'A

Which of the following would create a list named numbers consisting of 3 floating-point items?

numbers = [5.3, 4.8, 6.7]

Lizzy 73 C Mike 98 A Joel 88 B+ Anne 93 A

``` What is the value of the total variable after the following code executes? prices = [10, 15, 12, 8] total = 0 i = 1 while i < len(prices): total += prices[i] i += 1 print(total) ```

Given the following list, what is the value of names[2]? | names = ["Lizzy", "Mike", "Joel", "Anne", "Donald Duck"]

Joel

To refer to an item in a list, you code the list name followed by

an index number in brackets, starting with the number 0

The primary difference between a tuple and a list is that a tuple

is immutable

To insert the item “melon” after “grapes” in the following list, you would use which of these methods? fruit = ["apple", "banana", "grapes", "mangos", "oranges"]

fruit.insert(3, "melon")

Which of the following is not true about a CSV file?

The csv module is a standard module so you don’t need to import it

To read the rows in a CSV file, you need to

get a reader object by using the reader() function of the csv module

``` Code Example 7-2 import pickle def main(): courses = [["Python", 3], ["Trig", 3], ["Physics", 4], ["Yoga", 2]] with open("classes.bin", "wb") as file: pickle.dump(courses, file) with open("classes.bin", "rb") as file: course_list = pickle.load(file) i = 0 while i < len(course_list): course = course_list[i] print(course[0], str(course[1]), end=" ") i += 2 ``` main() Refer to Code Example 7-2: What does the second with open statement do?

causes an exception if the file named classes.bin doesn’t exist

``` Code Example 7-1 import csv def main(): courses = [["Python", 3], ["Trig", 3], ["Physics", 4], ["Yoga", 2]] with open("courses.csv", "w", newline="") as file: writer = csv.writer(file) writer.writerows(courses) course_list = [] with open("courses.csv", newline="") as file: reader = csv.reader(file) for row in reader: course_list.append(row) for i in range(len(course_list) - 2): course = course_list[i] print(course[0] + " (" + str(course[1]) + ")") ``` main() Refer to Code Example 7-1. If the first with open statement works, what is written to the file?

The list named courses.

To work with a file when you’re using Python, you must do all but one of the following. Which one is it?

decode the data in the file

``` Code Example 7-1 import csv def main(): courses = [["Python", 3], ["Trig", 3], ["Physics", 4], ["Yoga", 2]] with open("courses.csv", "w", newline="") as file: writer = csv.writer(file) writer.writerows(courses) course_list = [] with open("courses.csv", newline="") as file: reader = csv.reader(file) for row in reader: course_list.append(row) for i in range(len(course_list) - 2): course = course_list[i] print(course[0] + " (" + str(course[1]) + ")") ``` main() Refer to Code Example 7-1. What happens if the courses.csv file doesn’t exist when the first with open statement is executed?

a new file named courses.csv is created

Python 3 Physics 4

``` Code Example 7-1 import csv def main(): courses = [["Python", 3], ["Trig", 3], ["Physics", 4], ["Yoga", 2]] with open("courses.csv", "w", newline="") as file: writer = csv.writer(file) writer.writerows(courses) course_list = [] with open("courses.csv", newline="") as file: reader = csv.reader(file) for row in reader: course_list.append(row) for i in range(len(course_list) - 2): course = course_list[i] print(course[0] + " (" + str(course[1]) + ")") ``` main() Refer to Code Example 7-1. What will display on the console after the code executes?

Python (3) | Trig (3)

writes the courses list to a binary file if the file named classes.bin doesn’t exist

A binary file is like a text file in all but one of the following ways. Which one is it?

A binary file stores numbers with binary notation.

Given the following 2-dimensional list of 3 rows and 3 columns, how would you write this list to a CSV file named prog.csv? programming = [["Python", "cop1000", 3], ["Java", "cop1020", 3], ["HTML5", "cop1040", 3]]

``` with open("prog.csv", "w", newline ="") as file: writer = csv.writer(file) writer.writerows(programming) ```

To read a list of lists that’s stored in a binary file, you use

the load() method of the pickle module

Which one of the following is not a benefit of using a with statement to open a file?

You don’t have to specify the path for the file.

A Python program should use try statements to handle

all exceptions that can’t be prevented by normal coding techniques

``` Code Example 8-1 import csv import sys FILENAME = "names.csv" def main(): try: names = [] with open(FILENAME, newline="") as file: reader = csv.reader(file) for row in reader: names.append(row) except FileNotFoundError as e: print("Could not find " + FILENAME + " file.") sys.exit() except Exception as e: print(type(e), e) sys.exit() print(names) if __name__ == "__main__": main() ``` Refer to Code Example 8-1. If the names.csv file is not in the same directory as the file that contains the Python code, what type of exception will be thrown and caught?

FileNotFoundError

``` Code Example 8-1 import csv import sys FILENAME = "names.csv" def main(): try: names = [] with open(FILENAME, newline="") as file: reader = csv.reader(file) for row in reader: names.append(row) except FileNotFoundError as e: print("Could not find " + FILENAME + " file.") sys.exit() except Exception as e: print(type(e), e) sys.exit() print(names) if __name__ == "__main__": main() ``` Refer to Code Example 8-1. If the for statement in the try clause refers to readers instead of reader, what type exception will be thrown and caught?

NameError

If a program attempts to read from a file that does not exist, which of the following will catch that error?

FileNotFoundError and OSError

It’s a common practice to throw your own exceptions to test error handling routines that

catch exceptions that are hard to produce otherwise

The finally clause of a try statement

is executed whether or not an exception has been thrown

To cancel the execution of a program in the catch clause of a try statement, you can use the

exit() function of the sys module

To throw an exception with Python code, you use the

raise statement

When an exception is thrown, Python creates an exception object that contains all but one of the following items of information. Which one is it?

the severity of the exception

Which of the following is the correct way to code a try statement that catches any type of exception that can occur in the try clause?

``` try: number = float(input("Enter a number: ")) print("Your number is: ", number) except: print("Invalid number.") ```

Which of the following is the correct way to code a try statement that displays the type and message of the exception that’s caught?

``` try: number = int(input("Enter a number: ")) print("Your number is: ", number) except Exception as e: print(type(e), e) ```

Within the try clause of a try statement, you code

a block of statements that might cause an exception

Code Example 9-1 print("{:12} {:>10} {:>5}".format("Item", "Price", "Qty")) print("{:12} {:10.2f} {:5d}".format("laptop", 499.99, 1)) print("{:12} {:10.2f} {:5d}".format("charger", 29.95, 3)) print("{:12} {:10.2f} {:5d}".format("leather case", 125.00, 1)) Refer to Code Example 9-1. What does :5d specify in the print statements of the last three lines? The value in this column

is an integer with 5 spaces allowed for its display.

Code Example 9-1 print("{:12} {:>10} {:>5}".format("Item", "Price", "Qty")) print("{:12} {:10.2f} {:5d}".format("laptop", 499.99, 1)) print("{:12} {:10.2f} {:5d}".format("charger", 29.95, 3)) print("{:12} {:10.2f} {:5d}".format("leather case", 125.00, 1)) Refer to Code Example 9-1. What does the 2f mean in the {:10.2f} specification? The value

is a floating-point number that should be displayed with 2 decimal places.

``` Code Example 9-2 number = float(input("Enter a number: ")) result1 = number * .15 result2 = result1 / 3 result3 = result1 + result2 print(result3) ``` Refer to Code Example 9-2. When this code is executed, which of the variables might contain approximate results instead of accurate results?

result1, result2, and result3

``` Code Example 9-2 number = float(input("Enter a number: ")) result1 = number * .15 result2 = result1 / 3 result3 = result1 + result2 print(result3) ``` Refer to Code Example 9-2. To be sure that the results are accurate to 2 decimal places, you should

round the result of each expression to 2 decimal places

``` Given that the locale module has been imported as lc, which block of code will display the number in this format? £34,567.89 ```

lc.setlocale(lc.LC_ALL, "uk") | print(lc.currency(34567.89, grouping=True))

If number equals .15605, which of the following will display it as: 16%

print("{:.0%}".format(number))

If number equals 3,237,945.76, which of the following will display it as: 3,237,945.76

print("{:,.2f}".format(number))

One of the ways to deal with the inaccuracies that may result from floating-point arithmetic operations is to

round the results of those calculations that may lead to more decimal places than you want in the final result

One of the ways to deal with the inaccuracies that may result from floating-point arithmetic operations is to

do the math with Decimal objects instead of floating-point numbers

To define a variable named number that contains 123.4567 as a decimal number, not a floating-point number, which block of code would you use?

from decimal import Decimal | number = Decimal(123.4567)

To round a decimal number that’s stored in a variable named number to 2 decimal places with normal business rounding, which statement would you use?

number = number.quantize(Decimal("1.00"), ROUND_HALF_UP)

Using floating-point numbers can lead to arithmetic errors because floating-point numbers

are approximate values

What will be displayed when this code is executed? name = "Name" ID = "ID" print("{:10} {:>5}".format(name, ID)) print("{:10} {:7d}".format("Liz", 234)) print("{:10} {:7d}".format("Mike", 23456))

Name ID Liz 234 Mike 23456

When you’re using Decimal objects in an arithmetic expression, you cannot use

floating-point values as operands

Which of the following is not a floating-point number?

-683

Which of the following modules lets you work with decimal numbers instead of floating-point numbers?

decimal

Which of the following modules provides a function for formatting currency in the US, UK, or parts of Europe?

locale

Which of the following modules provides a function for getting the square root of a number?

math

Which of the following will produce the same result as this code? import math as m area = m.pi * radius**2

area = m.pi * m.pow(radius, 2)

You can use the format() method of a string to format numbers in all but one of the following ways. Which one is it?

apply $ signs

A Unicode character is represented by a

2-digit code

Code Example 10-1 1. phone_number = input("Enter phone number: ").strip() 2. if len(phone_number) == 10: 3. phone_number = "(" + phone_number[:3] + ")" + phone_number[3:6] + "-" + phone_number[6:] 4. print("Phone number: ", phone_number) 5. else: 6. print("Phone number: ", "Phone number must be 10 digits") Refer to Code Example 10-1. If the user enters two extra spaces at the end of a phone number, what will happen?

The strip() method on line 1 will strip away the extra whitespace.

The length of the number will be greater than 10 so the else clause will execute.

Phone number: (555)123-4567

Given the following code, what will be displayed after the code executes? name = "Mervin the Magician" words = name.split() print(words[0] + ", you are quite a " + words[2].lower())

Mervin, you are quite a magician

``` Given the following code, what would display? car = "PORSCHE" color = "red" my_car = car.join(color) print(my_car) ```

rPORSCHEePORSCHEd

If word = "a horse", which of the following snippets of Python code will display this result? a horse! a horse! My kingdom for a horse!

print((word + "! ") * 2 + " My kingdom for " + word + "!")

The isdigit() method of a string returns

true if the string contains only digits

The join() method of a list can be used to combine

the items in the list into a string that’s separated by delimiters

To access the first three characters in a string that’s stored in a variable named message, you can use this code:

first_three = message[0:3]

To determine the length of a string that’s in a variable named city, you can use this code:

len(city)

To retrieve the fourth character in a string that’s stored in a variable named city, you can use this code:

city[3]

``` What is the value of s2 after the code that follows is executed? s1 = "118-45-9271" s2 = "" for i in s1: if i != '-': s2 += i s1.replace("-", ".") ```

118459271

``` What is the value of s3 after the code that follows is executed? s1 = "abc def ghi"; s2 = s1[1:5] s3 = s2.replace('b', 'z') print(s3) ```

zc d

What is the value of the variable named result after this code is executed? email = "marytechknowsolve.com" result = email.find("@")

-1

What is the value of the variable named result after this code is executed? email = "joel.murach@com" result = email.find("@") - email.find(".") print(result)

What will be displayed after the following code executes? book_name = "a tale for the knight" book = book_name.title() print(book)

A Tale For The Knight

Which of the Python examples that follow can not be used to create a string named n2?

``` numbers = [8, 17, 54, 22, 35] n2 = "".join(numbers) ```

``` Which of the following code snippets will result in this display: Countdown... 5... 4... 3... 2... 1... Blastoff! ```

``` counting = "54321" print("Countdown...") for char in counting: print(char + "...") print("Blastoff!") ```

Which of the following statements will modify the string that’s stored in a variable named s?

You can’t modify a string.

Which of the following will display this result? | B = 66

print("B = ", ord("B"))

You can use the split() method to split a string into a list of strings based on a specified

delimiter

A naive datetime object doesn’t account for

time zones and daylight savings time

``` Code Example 11-1 from datetime import datetime, time def main(): input("Press Enter to start...") start = datetime.now() month = start.strftime("%B") day = start.strftime("%d") hours = start.strftime("%I") minutes = start.strftime("%M") am_pm = start.strftime("%p") print("Start time:",month,day,"at",hours,":",minutes,am_pm) input("Press Enter to stop...") stop = datetime.now() month = stop.strftime("%B") day = stop.strftime("%d") hours = stop.strftime("%I") minutes = stop.strftime("%M") am_pm = stop.strftime("%p") print("Stop time: ",month,day,"at",hours,":",minutes,am_pm) elapsed_time = stop - start new_days = elapsed_time.days new_minutes = elapsed_time.seconds // 60 new_hours = new_minutes // 60 new_minutes = new_minutes % 60 print("Time elapsed: ") if new_days > 0: print("days:",new_days) print("hours:", new_hours, ", minutes:", new_minutes) if __name__ == "__main__": main() ``` Refer to Code Example 11-1: Which variable holds the value of the beginning day?

day

``` Code Example 11-1 from datetime import datetime, time def main(): input("Press Enter to start...") start = datetime.now() month = start.strftime("%B") day = start.strftime("%d") hours = start.strftime("%I") minutes = start.strftime("%M") am_pm = start.strftime("%p") print("Start time:",month,day,"at",hours,":",minutes,am_pm) input("Press Enter to stop...") stop = datetime.now() month = stop.strftime("%B") day = stop.strftime("%d") hours = stop.strftime("%I") minutes = stop.strftime("%M") am_pm = stop.strftime("%p") print("Stop time: ",month,day,"at",hours,":",minutes,am_pm) elapsed_time = stop - start new_days = elapsed_time.days new_minutes = elapsed_time.seconds // 60 new_hours = new_minutes // 60 new_minutes = new_minutes % 60 print("Time elapsed: ") if new_days > 0: print("days:",new_days) print("hours:", new_hours, ", minutes:", new_minutes) if __name__ == "__main__": main() ``` Refer to Code Example 11-1: If the timer is started on November 17 at 4:00 pm and stopped on November 18 at 6:30 pm, what will be displayed?

Time elapsed: days: 1 hours: 2, minutes: 30

``` Code Example 11-1 from datetime import datetime, time def main(): input("Press Enter to start...") start = datetime.now() month = start.strftime("%B") day = start.strftime("%d") hours = start.strftime("%I") minutes = start.strftime("%M") am_pm = start.strftime("%p") print("Start time:",month,day,"at",hours,":",minutes,am_pm) input("Press Enter to stop...") stop = datetime.now() month = stop.strftime("%B") day = stop.strftime("%d") hours = stop.strftime("%I") minutes = stop.strftime("%M") am_pm = stop.strftime("%p") print("Stop time: ",month,day,"at",hours,":",minutes,am_pm) elapsed_time = stop - start new_days = elapsed_time.days new_minutes = elapsed_time.seconds // 60 new_hours = new_minutes // 60 new_minutes = new_minutes % 60 print("Time elapsed: ") if new_days > 0: print("days:",new_days) print("hours:", new_hours, ", minutes:", new_minutes) if __name__ == "__main__": main() ``` Refer to Code Example 11-1: If the timer is started on November 17 at 4:00 pm and stopped on November 18 at 6:30 pm, what is the value of minutes at the end of the program?

``` Code Example 11-1 from datetime import datetime, time def main(): input("Press Enter to start...") start = datetime.now() month = start.strftime("%B") day = start.strftime("%d") hours = start.strftime("%I") minutes = start.strftime("%M") am_pm = start.strftime("%p") print("Start time:",month,day,"at",hours,":",minutes,am_pm) input("Press Enter to stop...") stop = datetime.now() month = stop.strftime("%B") day = stop.strftime("%d") hours = stop.strftime("%I") minutes = stop.strftime("%M") am_pm = stop.strftime("%p") print("Stop time: ",month,day,"at",hours,":",minutes,am_pm) elapsed_time = stop - start new_days = elapsed_time.days new_minutes = elapsed_time.seconds // 60 new_hours = new_minutes // 60 new_minutes = new_minutes % 60 print("Time elapsed: ") if new_days > 0: print("days:",new_days) print("hours:", new_hours, ", minutes:", new_minutes) if __name__ == "__main__": main() ``` Refer to Code Example 11-1: If the timer is started on November 17 at 4:00 pm and stopped on November 18 at 6:30 pm, what is the value of seconds at the end of the program?

seconds is undefined

``` Code Example 11-1 from datetime import datetime, time def main(): input("Press Enter to start...") start = datetime.now() month = start.strftime("%B") day = start.strftime("%d") hours = start.strftime("%I") minutes = start.strftime("%M") am_pm = start.strftime("%p") print("Start time:",month,day,"at",hours,":",minutes,am_pm) input("Press Enter to stop...") stop = datetime.now() month = stop.strftime("%B") day = stop.strftime("%d") hours = stop.strftime("%I") minutes = stop.strftime("%M") am_pm = stop.strftime("%p") print("Stop time: ",month,day,"at",hours,":",minutes,am_pm) elapsed_time = stop - start new_days = elapsed_time.days new_minutes = elapsed_time.seconds // 60 new_hours = new_minutes // 60 new_minutes = new_minutes % 60 print("Time elapsed: ") if new_days > 0: print("days:",new_days) print("hours:", new_hours, ", minutes:", new_minutes) if __name__ == "__main__": main() ``` Refer to Code Example 11-1: If the timer is started on November 17 at 4:00 pm and stopped three seconds later, what will display under Time elapsed:?

Time elapsed: | hours: 0, minutes: 0

February 8, 1998 fell on a Sunday. What would the following code display? from datetime import datetime birthday = datetime(1998, 2, 8) birthday = birthday.strftime("%B %d, %Y (%A)") print("Your birthday is:", birthday)

Your birthday is: February 08, 1998 (Sunday)

In 2017 New Year’s Day fell on a Sunday. What would the following code display? from datetime import datetime new_year = datetime(2017, 1, 1) day_of_week = new_year.strftime("New Year's Day is on a %A") print(new_year) print(day_of_week)

2017-01-01 00:00:00 | New Year's Day is on a Sunday

To compare two datetime objects, you

can use any of the comparison operators

To create a datetime object by parsing a string, you can use the

strptime() method of the datetime class

To create a datetime object for the current date and time, you can use the

now() method of the datetime class

To create a datetime object with a constructor, you have to pass this sequence of arguments to it:

year, month, day

To format a datetime object for the current date and time, you can use the

strftime() method of the datetime object

To store just the year, month, and day for a date, you use a

date object

To work with dates, you need to import

the date class from the datetime module

What will be displayed after the following code executes? from datetime import datetime today = datetime(2018, 4, 26) birthday = datetime(2018, 6, 21) wait_time = birthday - today days = wait_time.days print("There are", days, "days until your birthday!")

There are 56 days until your birthday!

What will the following code display if the user enters 21/11/2018 at the prompt? from datetime import datetime today = input("Enter today's date: ") this_day = datetime.strptime(today, "%m/%d/%Y") print(this_day)

ValueError: time data '21/11/2018' does not match format '%m/%d/%Y'

``` What will the following code display? from datetime import datetime this_day = date(2018, 2, 8) this_day = this_day.strptime("%B %d, %Y") print(this_day) ```

NameError: name 'date' is not defined

``` What would the following code display? from datetime import date this_day = date(2018, 2, 8) this_day = this_day.strftime("%B %d, %Y") print("Today is:", this_day) ```

Today is: February 08, 2018

When you create a datetime object by parsing a string, you pass the parsing method

a string that represents the date and a formatting string that determines the parsing

When you subtract one datetime object from another, you get

a timedelta object

You can access the parts of a date/time object by using its

attributes

A dictionary stores a collection of

unordered items

Code Example 12-1 1. flowers = {"red": "rose", "white": "lily", "yellow": "buttercup"} 2. print(flowers) 3. flowers["blue"] = "carnation" 4. print(flowers) 5. print("This is a red flower:", flowers.get("red", "none")) 6. key = "white" 7. if key in flowers: 8. flower = flowers[key] 9. print("This is a", key, "flower:", flower) 10. key = "green" 11. if key in flowers: 12. flower = flowers[key] 13. del flowers[key] 14. print(flower + " was deleted") 15. else: 16. print("There is no " + key + " flower") Refer to Code Example 12-1: Which of the following represents a key/value pair for the dictionary named flowers defined on line 1?

red/rose

Code Example 12-1 1. flowers = {"red": "rose", "white": "lily", "yellow": "buttercup"} 2. print(flowers) 3. flowers["blue"] = "carnation" 4. print(flowers) 5. print("This is a red flower:", flowers.get("red", "none")) 6. key = "white" 7. if key in flowers: 8. flower = flowers[key] 9. print("This is a", key, "flower:", flower) 10. key = "green" 11. if key in flowers: 12. flower = flowers[key] 13. del flowers[key] 14. print(flower + " was deleted") 15. else: 16. print("There is no " + key + " flower") Refer to Code Example 12-1: Which of the following will be displayed by the print statement on line 4?

{'blue': 'carnation', 'red': 'rose', 'white': 'lily', 'yellow': 'buttercup'}

This is a red flower: rose

This is a white flower: lily

Code Example 12-1 1. flowers = {"red": "rose", "white": "lily", "yellow": "buttercup"} 2. print(flowers) 3. flowers["blue"] = "carnation" 4. print(flowers) 5. print("This is a red flower:", flowers.get("red", "none")) 6. key = "white" 7. if key in flowers: 8. flower = flowers[key] 9. print("This is a", key, "flower:", flower) 10. key = "green" 11. if key in flowers: 12. flower = flowers[key] 13. del flowers[key] 14. print(flower + " was deleted") 15. else: 16. print("There is no " + key + " flower") Refer to Code Example 12-1: What is the last line that this code prints to the console?

There is no green flower

``` Code Example 12-2 1. flowers = {"white": "lily", "red": "rose", "blue": "carnation", "yellow": "buttercup"} 2. colors = list(flowers.keys()) 3. colors.sort() 4. show_colors = "Colors of flowers: " 5. for color in colors: 6. show_colors += color + " " 7. print(show_colors) 8. pick_color = input("Enter a color: ") 9. pick_color = pick_color.lower() 10. if pick_color in flowers: 11. name = flowers[pick_color] 12. print("Flower name: " + name) 13. else: 14. print("There is no " + pick_color + " flower.") ``` Refer to Code Example 12-2: What will the print statement on line 7 display?

Colors of flowers: blue red white yellow

Flower name: buttercup

Code Example 12-3 pets = { "dog": {"type": "poodle", "color": "white"}, "cat": {"type": "Siamese", "color": "black and white"}, "bird": {"type": "parrot", "color": "green"} } pet = pets["dog"] pet = pets["bird"] print(pet["color"], pet["type"]) Refer to Code Example 12-3: What will display after the code executes?

green parrot

pet = "cat" | print(pets[pet]["color"], pets[pet]["type"], pet)

Each item in a dictionary is

a key/value pair

How many items does the following dictionary contain? | flowers = {"red": "rose", "white": "lily", "yellow": "buttercup"}

If each row in a list of lists has exactly two columns, you can convert it to a dictionary by using the

dict() constructor

The items() method returns a

view object containing all of the key/value pairs in a dictionary

The keys() method returns a

The key in a dictionary can be

To avoid a KeyError when using the pop() method of a dictionary, you can

use the optional second argument to supply a default value

To convert a view object to a list, you can use the

list() constructor

To delete all items from a dictionary you can

use the clear() method