PCEP Certification Practice: Python SystemExit Exception Handling

Last update on September 19 2024 12:53:09 (UTC/GMT +8 hours)

PCEP Certification Practice Test - Questions, Answers and Explanations

Here is a collection of 16 questions with answers and explanations, focusing on the Python "SystemExit" exception from the built-in exceptions hierarchy. These questions vary in format, including single- and multiple-select, "Place" & "Gap fill", sorting, code insertion, and code fill.

Question 1: Which of the following best describes the SystemExit exception in Python?

Raised when the Python interpreter exits normally.
Raised when a program encounters an unexpected error.
Raised to indicate that the program has run out of memory.
Raised when an operation or function receives an argument that has the right type but an inappropriate value.

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Answer: A) Raised when the Python interpreter exits normally.

Explanation: The SystemExit exception is raised by the sys.exit() function when the Python interpreter is requested to exit normally. It can be caught in a try-except block if necessary, but this is generally used for clean termination of the program.

Question 2: Which of the following statements about SystemExit is true? (Select all that apply.)

SystemExit is inherited from the BaseException class.
SystemExit is used to terminate the interpreter.
Catching SystemExit prevents the program from terminating.
SystemExit cannot be caught using a try-except block.

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Answer: A) SystemExit is inherited from the BaseException class.
B) SystemExit is used to terminate the interpreter.
C) Catching SystemExit prevents the program from terminating.

Explanation:

SystemExit is indeed a subclass of BaseException, which is at the top of the Python exception hierarchy.
It is used to terminate the Python interpreter (typically through sys.exit()).
SystemExit can be caught in a try-except block, and when caught, it can prevent the program from terminating if handled.

Question 3: _________ is the function commonly used to trigger the SystemExit exception in Python programs.

os._exit()
sys.exit()
exit()

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Answer: B) sys.exit()

Explanation: The sys.exit() function is the standard way to exit a Python program. It raises the SystemExit exception, which can optionally take an exit code as an argument.

Question 4: When the __________ exception is raised, the Python interpreter exits, unless the exception is caught.

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Answer: SystemExit

Explanation: When SystemExit is raised, it signals that the Python interpreter should terminate. It can be caught in exceptional cases, but typically, it leads to normal program termination.

Question 5: Fill in the blanks in the following code to raise and catch a SystemExit exception.

import sys

try:
    sys.__________(0)
except SystemExit as e:
    print(f"Caught SystemExit with code {e.code}")

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Answer: sys.exit(0)

Explanation: The sys.exit(0) function raises a SystemExit exception, and the except SystemExit block catches it and accesses the exit code using e.code.

Question 6: Which of the following exit codes passed to sys.exit() would typically indicate a successful program execution?

0
1
255
-1

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Answer: A) 0

Explanation: An exit code of 0 typically signifies successful execution. Non-zero exit codes (such as 1 or higher) indicate errors or abnormal termination.

Question 7: Insert code that would raise the SystemExit exception and pass an exit code of 42.

import sys

# INSERT CODE HERE

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Answer: sys.exit(42)

Explanation: The sys.exit() function raises the SystemExit exception, and you can pass any integer (such as 42) as the exit code to indicate a specific termination reason.

Question 8: What type of argument can be passed to sys.exit() to raise a SystemExit exception?

Only integers.
Only strings.
Any value.
None, sys.exit() must be called without arguments.

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Answer: C) Any value.

Explanation: sys.exit() accepts any argument, whether it's an integer, a string, or another type. If a string or other non-integer is passed, it is printed as the message before exiting.

Question 9: Arrange the following steps in the correct order when sys.exit() is called.

The Python interpreter processes the exit code.
The SystemExit exception is raised.
The interpreter terminates.

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Answer:

The SystemExit exception is raised.
The Python interpreter processes the exit code.
The interpreter terminates.

Explanation: First, sys.exit() raises the SystemExit exception. If it isn't caught, the interpreter processes the exit code (if provided), and then the interpreter terminates.

Question 10: Which of the following statements about catching SystemExit are correct? (Select all that apply.)

You can catch SystemExit in a try-except block.
If you catch SystemExit, the program will continue execution.
SystemExit cannot be caught, but it can be ignored.
When caught, you can access the exit code using the .code attribute.

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Answer: A) You can catch SystemExit in a try-except block.
B) If you catch SystemExit, the program will continue execution.
D) When caught, you can access the exit code using the .code attribute.

Explanation: SystemExit can be caught like any other exception, allowing the program to continue. When caught, you can access the exit code via the .code attribute of the exception instance.

Question 11: The SystemExit exception is raised by _________ when it tries to terminate the program.

sys.exit()
exit()
both A and B

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Answer: C) both A and B

Explanation: Both sys.exit() and exit() raise the SystemExit exception. While sys.exit() is the official method, exit() is often used in interactive sessions.

Question 12: The SystemExit exception inherits directly from __________ rather than Exception.

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Answer: BaseException

Explanation: SystemExit is a direct subclass of BaseException and not Exception. This is because it is intended for handling interpreter exit rather than regular exception handling.

Question 13: Fill in the blanks to complete this code that prints the exit code from a caught SystemExit exception.

import sys

try:
    sys.exit(10)
except SystemExit as e:
    print(f"Exit code: {e.________}")

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Answer: e.code

Explanation: When SystemExit is caught, the .code attribute contains the exit code passed to sys.exit().

Question 14: Which of the following exit codes signifies a general error when passed to sys.exit()?

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Answer: B) 1

Explanation: An exit code of 1 generally indicates a general error or failure, while 0 indicates success. Higher codes might indicate specific error conditions.

Question 15: Insert the missing code to prevent a program from exiting when SystemExit is raised.

import sys

try:
    sys.exit(5)
# INSERT CODE HERE

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Answer:

except SystemExit as e:
    print("Caught SystemExit")

Explanation: Catching the SystemExit exception prevents the program from terminating. Here, it simply prints a message instead of exiting.

Question 16: What will happen if SystemExit is not caught? (Select all that apply.)

The Python interpreter will terminate.
The exit code will be returned to the operating system.
The program will continue executing after sys.exit().
The program will raise an error message before exiting.

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Answer: A) The Python interpreter will terminate.
B) The exit code will be returned to the operating system.

Explanation: If SystemExit is not caught, the Python interpreter terminates, and the exit code is returned to the operating system.