Week 6

Question 1

If a file with the specified name already exists when the file is opened and the file is opened in ‘w’ mode, then an alert will appear on the screen.

Answer 1

False

Question 2

When a piece of data is read from a file, it is copied from the file into the program.

Answer 2

False

Question 3

Closing a file disconnects the communication between the file and the program.

Answer 3

True

Question 4

In Python, there is nothing that can be done if the program tries to access a file to read that does not exist.

Answer 4

False

Question 5

Python allows the programmer to work with text and number files.

Answer 5

False

Question 6

The ZeroDivisionError exception is raised when the program attempts to perform the calculation x/y if y = 0.

Answer 6

True

Question 7

An exception handler is a piece of code that is written using the try/except statement.

Answer 7

True

Question 8

If the last line in a file is not terminated with \n, the readline method will return the line without \n.

Answer 8

True

Question 9

Strings can be written directly to a file with the write method, but numbers must be converted to strings before they can be written.

Answer 9

True

Question 10

It is possible to create a while loop that determines when the end of a file has been reached.

Answer 10

True

Question 11

Which of the following is associated with a specific file and provides a way for the program to work with that file?
a. the filename
b. the file extension
c. the file object
d. the file variable

Answer 11

c. the file object

Question 12

What is the process of retrieving data from a file called?
a. retrieving data
b. reading data
c. reading input
d. getting data

Answer 12

b. reading data

Question 13

Which of the following describes what happens when a piece of data is written to a file?
a. The data is copied from a variable in RAM to a file.
b. The data is copied from a variable in the program to a file.
c. The data is copied from the program to a file.
d. The data is copied from a file object to a file.

Answer 13

a. The data is copied from a variable in RAM to a file.

Question 14

Which step creates a connection between a file and a program?
a. open the file
b. read the file
c. process the file
d. close the file

Answer 14

a. open the file

Question 15

How many types of files are there?
a. one
b. two
c. three
d. more than three

Answer 15

b. two

Question 16

A(n) __________ access file is also known as a direct access file.
a. sequential
b. random
c. numbered
d. text

Answer 16

b. random

Question 17

Which type of file access jumps directly to a piece of data in the file without having to read all the data that comes before it?
a. sequential
b. random
c. numbered
d. text

Answer 17

b. random

Question 18

A single piece of data within a record is called a
a. variable
b. delimiter
c. field
d. data bit

Answer 18

c. field

Question 19

Which mode specifier will erase the contents of a file if it already exists and create the file if it does not already exist?
a. ‘w’
b. ‘r’
c. ‘a’
d. ‘e’

Answer 19

a. ‘w’

Question 20

Which mode specifier will open a file but not let you change the file or write to it?
a. ‘w’
b. ‘r’
c. ‘a’
d. ‘e’

Answer 20

b. ‘r’

Question 21

Which method could be used to strip specific characters from the end of a string?
a. estrip
b. rstrip
c. strip
d. remove

Answer 21

b. rstrip

Question 22

Which method could be used to convert a numeric value to a string?
a. str
b. value
c. num
d. chr

Answer 22

a. str

Question 23

Which method will return an empty string when it has attempted to read beyond the end of a file?
a. read
b. getline
c. input
d. readline

Answer 23

d. readline

Question 24

Which statement can be used to handle some of the runtime errors in a program?
a. an exception statement
b. a try statement
c. a try/except statement
d. an exception handler statement

Answer 24

c. a try/except statement

Question 25

Given that the customer file references a file object, and the file was opened using the ‘w’ mode specifier, how would you write the string ‘Mary Smith’ to the file?
a. customer file.write(‘Mary Smith’)
b. customer.write(‘w’, ‘Mary Smith’)
c. customer.input(‘Mary Smith’)
d. customer.write(‘Mary Smith’)

Answer 25

d. customer.write(‘Mary Smith’)

Question 26

When a file has been opened using the ‘r’ mode specifier, which method will return the file’s contents as a string?
a. write
b. input
c. get
d. read

Answer 26

d. read

Question 27

Which of the following is the correct way to open a file named users.txt in ‘r’ mode?
a. infile = open(‘r’, users.txt)
b. infile = read(‘users.txt’, ‘r’)
c. infile = open(‘users.txt’, ‘r’)
d. infile = readlines(‘users.txt’, r)

Answer 27

c. infile = open(‘users.txt’, ‘r’)

Question 28

Which of the following is the correct way to open a file named users.txt to write to it?
a. outfile = open(‘w’, users.txt)
b. outfile = write(‘users.txt’, ‘w’)
c. outfile = open(‘users.txt’, ‘w’)
d. outfile = open(‘users.txt’)

Answer 28

c. outfile = open(‘users.txt’, ‘w’)

Question 29

What will be the output after the following code is executed and the user enters 75 and 0 at the first two prompts?
def main():
try:
total = int(input(“Enter total cost of items? “))
num_items = int(input(“Number of items “))
average = total / num_items
except ZeroDivisionError:
print(‘ERROR: cannot have 0 items’)
except ValueError:
print(‘ERROR: number of items cannot be negative’)
main()

Answer 29

ERROR: cannot have 0 items

Question 30

What will be the output after the following code is executed and the user enters 75 and -5 at the first two prompts?
def main():
try:
total = int(input(“Enter total cost of items? “))
num_items = int(input(“Number of items “))
average = total / num_items
except ZeroDivisionError:
print(‘ERROR: cannot have 0 items’)
except ValueError:
print(‘ERROR: number of items cannot be negative’)
main()

Answer 30

Nothing, there is no print statement to display average. The ValueError will not catch the error.

Question 31

When a program needs to save data for later use, it writes the data in a(n) ___________.

Answer 31

file

Question 32

Programmers usually refer to the process of __________ data in a file as writing data to the file.

Answer 32

saving

Question 33

When data is written to a file, it is described as a(n) __________ file.

Answer 33

output

Question 34

If data is retrieved from a file by a program, this is known by the term __________ file.

Answer 34

input

Question 35

A(n) ___________ file contains data that has been encoded as text, using a scheme such as ASCII.

Answer 35

text

Question 36

A(n) ___________ access file retrieves data from the beginning of the file to the end of the file.

Answer 36

sequential

Question 37

A(n) __________ file contains data that has not been converted to text.

Answer 37

binary

Question 38

A filename __________ is a short sequence of characters that appear at the end of a filename, preceded by a period.

Answer 38

extension

Question 39

A(n) __________ gives information about the line number(s) that caused an exception.

Answer 39

traceback

Question 40

A(n) ___________ block includes one or more statements that can potentially raise an exception.