Exception Handling in Python

Topics in this chapter

• Try-Except Blocks and Built-in Exceptions
• Else and Finally Blocks in Exception Handling
• Raising Exceptions and User-Defined Custom Exceptions
• Exception Propagation and Control Flow
• Advanced Exception Handling and Best Practices

Cheat sheet

Practice questions

1. Question 1Q-4D2F62

   What is the main purpose of the finally block in Python exception handling?

   1. A.It executes only when an exception occurs.
   2. B.It executes only when no exception occurs.
   3. C.It executes whether or not an exception occurs.
   4. D.It is used only to define custom exceptions.
   See the answer and solution
2. Question 2Q-F79368

   What will be the output of the following Python code? try: value = int("10") except ValueError: print("invalid") else: print(value / 4) finally: print("finished")

   1. A.invalid finished
   2. B.2.5 finished
   3. C.2 finished
   4. D.finished
   See the answer and solution
3. Question 3Q-291D67

   Explain why specific exception classes should generally be handled before a general exception class such as Exception. Include a short Python example showing the correct order.

   See the answer and solution
4. Question 4Q-E4AC3C

   What is printed by the following Python code? try: number = int("abc") except ValueError: print("A") except TypeError: print("B")

   1. A.A
   2. B.B
   3. C.abc
   4. D.The program terminates without output
   See the answer and solution
5. Question 5Q-6E2DC5

   What is printed by the following Python code? try: try: int("x") except ValueError: raise RuntimeError("bad input") except RuntimeError as error: print(type(error).name)

   1. A.ValueError
   2. B.RuntimeError
   3. C.bad input
   4. D.No output because the inner exception is ignored
   See the answer and solution