PCEP-30-02 2.2 iterations in Python.txt

PCEP-30-02 2.2 iterations in Python, including while loops, for loops, range(), iterating through sequences, loop control statements, nested loops, and conditional statements within loops:

1. What is the purpose of the `pass` statement in Python?
   A) To skip the rest of the loop
   B) To continue to the next iteration
   C) To do nothing and act as a placeholder
   D) To exit the loop immediately

2. Which of the following is a valid `while` loop in Python?
   A) `while x < 10:`
   B) `while (x < 10)`
   C) `while x < 10 do:`
   D) Both A and B

3. How many times will the following loop iterate?
   ```python
   for i in range(5):
       print(i)
   ```
   A) 4 times
   B) 5 times
   C) 6 times
   D) Infinite times

4. What will be the output of the following code?
   ```python
   for letter in "Python":
       if letter == "h":
           continue
       print(letter, end="")
   ```
   A) Python
   B) Pyton
   C) Pythn
   D) Pyto

5. Which statement is used to immediately terminate a loop in Python?
   A) stop
   B) exit
   C) break
   D) end

6. What does the `else` clause in a `for` loop do?
   A) It executes if the loop completes normally (without a break)
   B) It always executes after the loop
   C) It executes if the loop is empty
   D) It executes if an exception occurs in the loop

7. How can you iterate through a list in reverse order?
   A) `for item in list.reverse():`
   B) `for item in reversed(list):`
   C) `for item in list[::-1]:`
   D) Both B and C

8. What will be the output of this nested loop?
   ```python
   for i in range(3):
       for j in range(2):
           print(i, j)
   ```
   A) 0 0, 0 1, 1 0, 1 1, 2 0, 2 1
   B) 0 0, 1 0, 2 0, 0 1, 1 1, 2 1
   C) 0 0, 0 1, 1 1, 1 2, 2 2, 2 3
   D) 0 0, 1 1, 2 2

9. Which of the following is NOT a valid way to iterate through a list in Python?
   A) `for item in my_list:`
   B) `for i in range(len(my_list)):`
   C) `while my_list:`
   D) `for index, value in my_list:`

10. What does the `enumerate()` function do in a for loop?
    A) It counts the number of iterations
    B) It provides both the index and value of each item
    C) It enumerates the list items
    D) It creates an enumerated type

11. How can you create an infinite loop in Python?
    A) `while True:`
    B) `for i in range(infinity):`
    C) `loop:`
    D) `repeat:`

12. What will be the output of this code?
    ```python
    x = 0
    while x < 5:
        x += 1
        if x == 3:
            continue
        print(x, end=" ")
    ```
    A) 1 2 3 4 5
    B) 1 2 4 5
    C) 1 2 3 4
    D) 1 2 4

13. Which of the following is a correct way to iterate through a dictionary in Python?
    A) `for key in dict:`
    B) `for key, value in dict.items():`
    C) `for key in dict.keys():`
    D) All of the above

14. What does the `range(1, 10, 2)` function call produce?
    A) 1, 3, 5, 7, 9
    B) 1, 2, 3, 4, 5, 6, 7, 8, 9
    C) 2, 4, 6, 8
    D) 1, 3, 5, 7

15. In a nested loop structure, which statement will break out of the innermost loop only?
    A) break
    B) continue
    C) pass
    D) return

16. What will be the output of this code?
    ```python
    for i in range(3):
        print(i)
    else:
        print("Done")
    ```
    A) 0 1 2
    B) 0 1 2 Done
    C) 0 1 2 3 Done
    D) Done

17. Which of the following is NOT a valid loop control statement in Python?
    A) break
    B) continue
    C) pass
    D) skip

18. What does the `zip()` function do when used in a for loop?
    A) It compresses the loop
    B) It iterates over two or more sequences in parallel
    C) It creates a zip file
    D) It speeds up the loop execution

19. How can you create a loop that iterates 5 times, starting from 1?
    A) `for i in range(1, 6):`
    B) `for i in range(5):`
    C) `for i in range(1, 5):`
    D) `for i in range(0, 5):`

20. What will be the output of this code?
    ```python
    i = 0
    while i < 5:
        print(i, end=" ")
        i += 1
    else:
        print("Done")
    ```
    A) 0 1 2 3 4
    B) 0 1 2 3 4 Done
    C) 1 2 3 4 5 Done
    D) 0 1 2 3 4 5 Done

21. Which statement is used to skip the rest of the code inside a loop for the current iteration only?
    A) break
    B) continue
    C) pass
    D) skip

22. What will be the output of this comprehension?
    ```python
    [x for x in range(10) if x % 2 == 0]
    ```
    A) [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
    B) [0, 2, 4, 6, 8]
    C) [1, 3, 5, 7, 9]
    D) [2, 4, 6, 8]

23. How can you iterate over both the keys and values of a dictionary simultaneously?
    A) `for k, v in dict:`
    B) `for k, v in dict.items():`
    C) `for k, v in dict.keys(), dict.values():`
    D) `for k, v in enumerate(dict):`

24. What will be the output of this nested conditional in a loop?
    ```python
    for i in range(3):
        if i == 1:
            if i + 1 == 2:
                print("Yes")
            else:
                print("No")
    ```
    A) Yes
    B) No
    C) Yes No
    D) No Yes

25. Which of the following is true about the `pass` statement in Python?
    A) It raises an exception
    B) It terminates the program
    C) It does nothing and is used as a placeholder
    D) It skips to the next iteration of the loop

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