Chapter 6

Question 1

Why must programs use files?

Answer 1

To retain data between program runs

Question 2

What is writing data to a file?

Answer 2

Saving data on a file (output file)

Question 3

What is reading data from a file?

Answer 3

Retrieving data from a file (input file)

Question 4

What are the three steps when a program uses a file?

Answer 4

Open the file, process the file, close the file

Question 5

What are the two main types of files?

Answer 5

Text files and binary files

Question 6

What are the two ways to access file data?

Answer 6

Sequential access and direct access

Question 7

What is a filename extension?

Answer 7

A short sequence of characters at the end of a filename indicating file type

Question 8

What does Python’s open() function do?

Answer 8

Opens a file, creates a file object, and associates it with a disk file

Question 9

What are the common file modes in Python?

Answer 9

‘r’ for reading, ‘w’ for writing, ‘a’ for appending

Question 10

What happens when you open a file with ‘w’ mode?

Answer 10

If it exists, it is overwritten; if not, it is created

Question 11

What happens when you open a file with ‘a’ mode?

Answer 11

Data is written to the end of the file without erasing existing content

Question 12

What does write() do?

Answer 12

Writes a string to a file

Question 13

What does read() do?

Answer 13

Reads the entire file into a string

Question 14

What does readline() do?

Answer 14

Reads one line from a file, including the \n

Question 15

What does rstrip() do when reading files?

Answer 15

Strips trailing characters (like \n) from a string

Question 16

Why must numbers be converted before writing to a file?

Answer 16

They must be converted to strings using str()

Question 17

Why must numbers be converted after reading from a file?

Answer 17

They are read as strings and must be converted with int() or float()

Question 18

How does Python detect the end of a file using readline()?

Answer 18

An empty string ‘’ is returned

Question 19

How do you use a for loop to read files?

Answer 19

for line in file_object:
statements

Question 20

What does the with statement do when opening files?

Answer 20

Opens and automatically closes files when the block ends

Question 21

What is a record?

Answer 21

A set of data that describes one item

Question 22

What is a field?

Answer 22

A single piece of data within a record

Question 23

What is an exception in Python?

Answer 23

An error that occurs during program execution

Question 24

What is a traceback?

Answer 24

An error message showing the type of exception and line number

Question 25

What is an exception handler?

Answer 25

Code that responds when exceptions are raised to prevent program crashes

Question 26

What is the general format of try/except?

Answer 26

try: statements except ExceptionName: statements

Question 27

What happens if no exception occurs in a try block?

Answer 27

The except block is skipped

Question 28

What is multiple exception handling?

Answer 28

Writing multiple except clauses for different exception types

Question 29

How can you display an exception’s default error message?

Answer 29

Assign the exception object to a variable and print it (except ValueError as err: print(err))

Question 30

What does the else clause do in exception handling?

Answer 30

Executes only if no exceptions were raised

Question 31

What does the finally clause do?

Answer 31

Executes regardless of whether an exception occurred; used for cleanup

Question 32

What happens if an exception is not handled?

Answer 32

The program halts with an error message