PCEP-30-02 4.2 section, covering pa.txt

PCEP-30-02 4.2 section, covering parameters vs. arguments, positional, keyword, and mixed argument passing, default parameter values, name scopes, name hiding (shadowing), and the global keyword:

1. What is the difference between parameters and arguments in Python functions?
   A) Parameters are defined in the function, arguments are passed when calling the function
   B) Arguments are defined in the function, parameters are passed when calling the function
   C) They are the same thing
   D) Parameters are for built-in functions, arguments are for user-defined functions

2. Which of the following is an example of positional argument passing?
   A) func(x=5, y=10)
   B) func(5, 10)
   C) func(*args)
   D) func(**kwargs)

3. What is the output of this code?
   ```python
   def greet(name, greeting="Hello"):
       print(f"{greeting}, {name}!")
   
   greet("Alice")
   ```
   A) Hello, Alice!
   B) Alice, Hello!
   C) Error
   D) None

4. Which of the following is an example of keyword argument passing?
   A) func(5, 10)
   B) func(x=5, y=10)
   C) func(5, y=10)
   D) func(*[5, 10])

5. What is the output of this code?
   ```python
   def func(a, b, c=3):
       print(a, b, c)
   
   func(1, c=5, b=2)
   ```
   A) 1 2 5
   B) 1 5 2
   C) Error
   D) 1 2 3

6. Which of the following allows a function to accept any number of keyword arguments?
   A) def func(**kwargs):
   B) def func(*args):
   C) def func(args):
   D) def func(...):

7. What is the purpose of default parameter values?
   A) To make parameters optional
   B) To increase function performance
   C) To prevent errors
   D) To override global variables

8. What is the output of this code?
   ```python
   x = 10
   def func():
       x = 20
       print(x)
   
   func()
   print(x)
   ```
   A) 20, 20
   B) 20, 10
   C) 10, 10
   D) Error

9. Which of the following is an example of mixed argument passing?
   A) func(1, 2, 3)
   B) func(a=1, b=2, c=3)
   C) func(1, b=2, c=3)
   D) func(*args)

10. What happens if you provide fewer arguments than parameters in a function call?
    A) The function uses default values for missing arguments if available
    B) The function always raises a TypeError
    C) The function ignores the missing arguments
    D) The function returns None

11. What is name shadowing in Python?
    A) When a local variable has the same name as a global variable
    B) When a function has the same name as a variable
    C) When two functions have the same name
    D) When a variable is not defined

12. Which keyword is used to modify a global variable from within a function?
    A) global
    B) nonlocal
    C) extern
    D) public

13. What is the output of this code?
   ```python
   def func(a, b, *, c):
       print(a, b, c)
   
   func(1, 2, c=3)
   ```
   A) 1 2 3
   B) Error
   C) 1 2
   D) None

14. What does the * operator do when used in a function definition?
    A) It multiplies the parameters
    B) It allows the function to accept any number of positional arguments
    C) It makes all parameters optional
    D) It raises the parameters to a power

15. What is the output of this code?
    ```python
    x = 10
    def func():
        global x
        x = 20
        print(x)
    
    func()
    print(x)
    ```
    A) 20, 20
    B) 20, 10
    C) 10, 10
    D) Error

16. Which of the following is true about default parameter values?
    A) They must be immutable objects
    B) They are evaluated every time the function is called
    C) They can be any Python expression
    D) They can only be used with keyword arguments

17. What is the output of this code?
    ```python
    def func(a, b=2, *args, **kwargs):
        print(a, b, args, kwargs)
    
    func(1, 3, 4, 5, x=6, y=7)
    ```
    A) 1 3 (4, 5) {'x': 6, 'y': 7}
    B) 1 2 (3, 4, 5) {'x': 6, 'y': 7}
    C) Error
    D) 1 3 4 5 {'x': 6, 'y': 7}

18. What happens if you try to modify a mutable default argument in a function?
    A) It raises an error
    B) The change is reflected in subsequent function calls
    C) The change is only local to that function call
    D) It creates a new copy of the argument

19. What is the purpose of the nonlocal keyword?
    A) To access global variables
    B) To create a new global variable
    C) To modify a variable in the nearest enclosing scope
    D) To prevent variable shadowing

20. What is the output of this code?
    ```python
    def outer():
        x = "local"
        def inner():
            nonlocal x
            x = "nonlocal"
        inner()
        print(x)
    
    outer()
    ```
    A) local
    B) nonlocal
    C) Error
    D) None

21. Which of the following is true about positional-only parameters?
    A) They must be the first parameters in a function definition
    B) They can be mixed with keyword parameters
    C) They are indicated by / in the function definition
    D) They cannot have default values

22. What is the output of this code?
    ```python
    def func(a, b, **kwargs):
        print(a, b, kwargs.get('c', 3))
    
    func(1, 2)
    ```
    A) 1 2 3
    B) 1 2 None
    C) Error
    D) 1 2

23. What happens if you provide more positional arguments than parameters in a function call?
    A) The extra arguments are ignored
    B) The function raises a TypeError
    C) The extra arguments are packed into a tuple if *args is used
    D) The function returns None

24. What is the purpose of the * in a function call?
    A) To unpack a list or tuple into separate arguments
    B) To indicate variable-length arguments
    C) To multiply arguments
    D) To make arguments optional

25. What is the output of this code?
    ```python
    x = 10
    def func():
        x = 20
        def inner():
            global x
            x = 30
        inner()
        print(x)
    
    func()
    print(x)
    ```
    A) 20, 30
    B) 20, 10
    C) 30, 30
    D) 20, 20

Answers:
1. A, 2. B, 3. A, 4. B, 5. A, 6. A, 7. A, 8. B, 9. C, 10. A, 11. A, 12. A, 13. A, 14. B, 15. A, 16. A, 17. A, 18. B, 19. C, 20. B, 21. C, 22. A, 23. B, 24. A, 25. C