Test

Quick check

1. 1. What is the output of the following code? def recursive_sum(n): if n <= 1: return n else: return n + recursive_sum(n - 1) print(recursive_sum(5))

   10152025

2. 2. What will be the output of the following code? class Animal: def speak(self): print("Animal speaks") class Dog(Animal): def speak(self): print("Dog barks") class Labrador(Dog): pass lab = Labrador() lab.speak()

   Animal speaksDog barksLabrador barksError

3. 3. What is the output of the following code? def modify_list(lst): lst.append(4) lst = [1, 2, 3] print("Inside function:", lst) my_list = [1, 2, 3] modify_list(my_list) print("Outside function:", my_list)

   Inside function: [1, 2, 3], Outside function: [1, 2, 3]Inside function: [1, 2, 3], Outside function: [1, 2, 3, 4]Inside function: [1, 2, 3, 4], Outside function: [1, 2, 3, 4]Inside function: [1, 2, 3], Outside function: [1, 2, 3]

4. 4. What is the purpose of the `__init__` method in Python classes?

   To initialize class variablesTo define class methodsTo create a new instance of the classTo delete the class instance

5. 5. What is the output of the following code? x = [1, 2, 3] y = x y.append(4) print(x)

   [1, 2, 3][1, 2, 3, 4][4, 1, 2, 3]Error

6. 6. Which of the following is true about Python sets?

   Sets are ordered collectionsSets can contain duplicate elementsSets are mutableSets can only contain numbers

7. 7. What is the output of the following code? def outer(): x = 1 def inner(): nonlocal x x = 2 print("Inner:", x) inner() print("Outer:", x) outer()

   Inner: 1, Outer: 1Inner: 2, Outer: 1Inner: 2, Outer: 2Error

8. 8. What is the purpose of the `super()` function in Python?

   To call a superclass methodTo create a new instance of a classTo define a new classTo delete a class instance

9. 9. What is the output of the following code? class A: def __init__(self): self.x = 1 class B(A): def __init__(self): super().__init__() self.y = 2 b = B() print(b.x, b.y)

   1 21 NoneNone 2Error

10. 10. What is the time complexity of accessing an element in a dictionary by its key?

    O(1)O(n)O(log n)O(n^2)

11. 11. What is the output of the following code? def generator(): yield 1 yield 2 yield 3 g = generator() print(next(g)) print(next(g))

    1 11 21 3Error

12. 12. Which of the following is NOT a valid way to create a set in Python?

    set(){1, 2, 3}set([1, 2, 3]){1: 'one', 2: 'two'}

13. 13. What is the output of the following code? class MyClass: class_var = 0 def __init__(self): self.instance_var = 0 def increment(self): self.instance_var += 1 self.class_var += 1 obj1 = MyClass() obj2 = MyClass() obj1.increment() obj2.increment() print(obj1.instance_var, obj1.class_var) print(obj2.instance_var, obj2.class_var)

    1 1, 1 11 2, 1 21 1, 1 21 2, 1 1

14. 14. What is the purpose of the `__str__` method in Python classes?

    To define how an object should be represented as a stringTo initialize class variablesTo compare two objectsTo delete an object

15. 15. What is the output of the following code? def decorator(func): def wrapper(): print("Before") func() print("After") return wrapper @decorator def say_hello(): print("Hello") say_hello()

    HelloBefore Hello AfterBefore After HelloError

16. 16. Which of the following is true about Python's garbage collection?

    It uses reference countingIt uses a mark-and-sweep algorithmIt uses both reference counting and generational garbage collectionPython doesn't have garbage collection

17. 17. What is the output of the following code? import copy original = [[1, 2, 3], [4, 5, 6]] shallow = copy.copy(original) deep = copy.deepcopy(original) original[0][1] = 10 print(shallow[0][1], deep[0][1])

    2 210 210 10Error

18. 18. What is the purpose of the `__slots__` attribute in Python classes?

    To define class methodsTo restrict the attributes that can be added to an instanceTo create class variablesTo define abstract methods

19. 19. What is the output of the following code? class Meta(type): def __new__(cls, name, bases, attrs): attrs['x'] = 10 return super().__new__(cls, name, bases, attrs) class MyClass(metaclass=Meta): pass obj = MyClass() print(obj.x)

    10NoneError0

20. 20. Which of the following is NOT a valid magic method in Python?

    __init____str____eq____create__

21. 21. What is the output of the following code? def func(a, b, c=3, d=4): print(a, b, c, d) func(1, *(5,), **{'c': 9})

    1 5 3 41 5 9 4Error1 5 3 9

22. 22. What is the purpose of the `contextlib` module in Python?

    To handle file I/O operationsTo create and manage context managersTo handle network connectionsTo manage database connections

23. 23. What is the output of the following code? class A: def __init__(self): print("A") super().__init__() class B: def __init__(self): print("B") super().__init__() class C(A, B): def __init__(self): print("C") super().__init__() C()

    C A BC B AA B CError

24. 24. Which of the following is true about Python's Global Interpreter Lock (GIL)?

    It allows multiple threads to execute Python bytecode at onceIt prevents multiple threads from executing Python bytecode at onceIt only affects CPython implementationBoth b and c

25. 25. What is the output of the following code? import asyncio async def foo(): print("start") await asyncio.sleep(1) print("end") asyncio.run(foo())

    startendstart endError

26. 26. What is the purpose of the `__all__` variable in Python modules?

    To define all variables in a moduleTo specify which names should be imported when using `from module import *`To create a list of all functions in a moduleTo define abstract methods in a class

27. 27. What is the output of the following code? class MyDict(dict): def __setitem__(self, key, value): super().__setitem(key, value * 2) d = MyDict() d['a'] = 1 print(d['a'])

    12NoneError

28. 28. Which of the following is true about Python's memory management?

    Python uses manual memory managementPython uses automatic garbage collectionPython doesn't have memory managementPython uses static memory allocation

29. 29. What is the output of the following code? from functools import lru_cache @lru_cache(maxsize=None) def fib(n): if n < 2: return n return fib(n-1) + fib(n-2) print(fib(100))

    354224848179261915075Error: maximum recursion depth exceeded1000

30. 30. What is the purpose of the `__slots__` attribute in Python classes?

    To define class methodsTo restrict the attributes that can be added to an instanceTo create class variablesTo define abstract methods