linkedin-skill-assessments-quizzes

Python (Programming Language)

Q1. What is an abstract class?

reference

Q2. What happens when you use the built-in function any() on a list?

example

if any([True, False, False, False]) == True:
    print('Yes, there is True')
>>> 'Yes, there is True'

Q3. What data structure does a binary tree degenerate to if it isn’t balanced properly?

reference

Q4. What statement about static methods is true?

reference

Q5. What are attributes?

Explanation: Attributes are defined under the class, and arguments go under the functions. arguments usually refer to parameters, whereas attributes are the constructors of the class or an instance of a class.

Q6. What is the term to describe this code?

count, fruit, price = (2, 'apple', 3.5)

Reference

Q7. What built-in list method would you use to remove items from a list?

Reference

example

my_list = [1,2,3]
my_list.pop(0)
my_list
>>>[2,3]

Q8. What is one of the most common uses of Python’s sys library?

reference

Q9. What is the runtime of accessing a value in a dictionary by using its key?

Q10. What is the correct syntax for defining a class called Game, if it inherits from a parent class called LogicGame?

Explanation: The parent class which is inherited is passed as an argument to the child class. Therefore, here the first option is the right answer.

Q11. What is the proper format for writing a doctest?

def sum(a, b):
    """
    sum(4, 3)
    7

    sum(-4, 5)
    1
    """
    return a + b

def sum(a, b):
    """
    >>> sum(4, 3)
    7

    >>> sum(-4, 5)
    1
    """
    return a + b

def sum(a, b):
    """
    # >>> sum(4, 3)
    # 7

    # >>> sum(-4, 5)
    # 1
    """
    return a + b

def sum(a, b):
    ###
    >>> sum(4, 3)
    7

    >>> sum(-4, 5)
    1
    ###
    return a + b

Explanation: Use ''' to start the doc and add the output of the cell after >>>

Q12. What built-in Python data type is commonly used to represent a stack?

Q13. What would this expression return?

college_years = ['Freshman', 'Sophomore', 'Junior', 'Senior']
return list(enumerate(college_years, 2019))

Q14. What is the purpose of the “self” keyword when defining or calling instance methods?

Reference

Simple example

class my_secrets:
    def __init__(self, password):
        self.password = password
        pass
instance = my_secrets('1234')
instance.password
>>>'1234'

Q15. Which of these is NOT a characteristic of namedtuples?

We need to import it using:from collections import namedtuple

Q16. What is an instance method?

Q17. Which statement does NOT describe the object-oriented programming concept of encapsulation?

Reference

Q18. What is the use of an if/else statement?

Reference

Q19. What built-in Python data type is best suited for implementing a queue?

Q20. What is the correct syntax for instantiating a new object of the type Game?

Reference

Q21. What does the built-in map() function do?

Reference

Explanation: - The syntax for map() function is list(map(function,iterable)). The simple area finder using a map would be like this

import math
radius = [1,2,3]
area = list(map(lambda x: round(math.pi*(x**2), 2), radius))
area
>>> [3.14, 12.57, 28.27]

Q22. If you don’t explicitly return a value from a function, what happens?

reference. When the return statement is None or has no value or there is no return statement the function returns None.

Q23. What is the purpose of the pass statement in Python?

The pass statement is used as a placeholder for future code. When the pass statement is executed, nothing happens, but you avoid getting an error when empty code is not allowed. reference

Q24. What is the term used to describe items that may be passed into a function?

Q25. Which collection type is used to associate values with unique keys?

Reference

Q26. When does a For loop stop iterating?

Reference

Q27. Assuming the node is in a singly linked list, what is the runtime complexity of searching for a specific node within a singly linked list?

Q28. Given the following three lists, how would you create a new list that matches the desired output printed below?

fruits = ['Apples', 'Oranges', 'Bananas']
quantities = [5, 3, 4]
prices = [1.50, 2.25, 0.89]

#Desired output
[('Apples', 5, 1.50),
('Oranges', 3, 2.25),
('Bananas', 4, 0.89)]

output = []

fruit_tuple_0 = (first[0], quantities[0], price[0])
output.append(fruit_tuple)

fruit_tuple_1 = (first[1], quantities[1], price[1])
output.append(fruit_tuple)

fruit_tuple_2 = (first[2], quantities[2], price[2])
output.append(fruit_tuple)

return output

i = 0
output = []
for fruit in fruits:
    temp_qty = quantities[i]
    temp_price = prices[i]
    output.append((fruit, temp_qty, temp_price))
    i += 1
return output

groceries = zip(fruits, quantities, prices)
return groceries

>>> [
('Apples', 5, 1.50),
('Oranges', 3, 2.25),
('Bananas', 4, 0.89)
]

i = 0
output = []
for fruit in fruits:
    for qty in quantities:
        for price in prices:
            output.append((fruit, qty, price))
    i += 1
return output

Q29. What happens when you use the built-in function all() on a list?

Reference

Explanation: all() returns True if all in the list are True. See example below:

test = [True, False, False, False]
if all(test) is True:
    print('Yeah, all of them are true.')
else:
    print('There is an imposter.')

>>> 'There is an imposter'

Q30. What is the correct syntax for calling an instance method on a class named Game?

(Answer format may vary. Game and roll (or dice_roll) should each be called with no parameters.)

>>> dice = Game()
>>> dice.roll()

>>> dice = Game(self)
>>> dice.roll(self)

>>> dice = Game()
>>> dice.roll(self)

>>> dice = Game(self)
>>> dice.roll()

Q31. What is the algorithmic paradigm of quick sort?

Both merge sort and quicksort employ a common algorithmic paradigm based on recursion. This paradigm, divide-and-conquer, breaks a problem into subproblems that are similar to the original problem, recursively solves the subproblems, and finally combines the solutions to the subproblems to solve the original problem. reference

Q32. What is the runtime complexity of the list’s built-in .append() method?

This function has constant time complexity i.e. O(1), because lists are randomly accessed so the last element can be reached in O(1) time that’s why the time taken to add the new element at the end of the list is O(1).

Q33. What is the key difference between a set and a list?

Q34. What is the definition of abstraction as applied to object-oriented Python?

Abstraction in Python is defined as a process of handling complexity by hiding unnecessary information from the user. reference

Q35. What does this function print?

def print_alpha_nums(abc_list, num_list):
    for char in abc_list:
        for num in num_list:
            print(char, num)
    return

print_alpha_nums(['a', 'b', 'c'], [1, 2, 3])

a 1
a 2
a 3
b 1
b 2
b 3
c 1
c 2
c 3

['a', 'b', 'c'], [1, 2, 3]

aaa
bbb
ccc
111
222
333

a 1 2 3
b 1 2 3
c 1 2 3

Q36. Pick the correct representation of doctest for a function in Python.

def sum(a, b):
    # a = 1
    # b = 2
    # sum(a, b) = 3

    return a + b

def sum(a, b):
    """
    a = 1
    b = 2
    sum(a, b) = 3
    """

    return a + b

def sum(a, b):
    """
    >>> a = 1
    >>> b = 2
    >>> sum(a, b)
    3
    """

    return a + b

def sum(a, b):
    '''
    a = 1
    b = 2
    sum(a, b) = 3
    '''
    return a + b

Explanation: Use """ to start and end the docstring and use >>> to represent the input. If you write this correctly you can also run the doctest using the build-in doctest module

Q37. Suppose a Game class inherits from two parent classes: BoardGame and LogicGame. Which statement is true about the methods of an object instantiated from the Game class?

Q38. What does calling namedtuple on a collection type return?

Example

# namedtuple function accepts the following arguments to generate a class
from collections import namedtuple
>>> Point = namedtuple('Point',['x','y'])
>>> point = Point(100, 200)
>>> point
    Point(x=100, y=200)

# Which lets you use both unpacking and iteration to access
>>> x, y = point
>>> print(f'({x}, {y})')
    (100, 200)
>>> for coordinate in point:
        print(coordinate)
    100
    200

Reference

Q39. What symbol(s) do you use to assess equality between two elements?

Q40. Review the code below. What is the correct syntax for changing the price to 1.5?

fruit_info = {
  'fruit': 'apple',
  'count': 2,
  'price': 3.5
}

Q41. What value would be returned by this check for equality?

5 != 6

Explanation: In Python, != is equivalent to not equal to.

Q42. What does a class’s __init__() method do?

Reference

Example:

class test:
    def __init__(self):
        print('I came here without your permission lol')
        pass
t1 = test()
>>> 'I came here without your permission lol'

Q43. What is meant by the phrase “space complexity”?

Q44. What is the correct syntax for creating a variable that is bound to a dictionary?

Q45. What is the proper way to write a list comprehension that represents all the keys in this dictionary?

fruits = {'Apples': 5, 'Oranges': 3, 'Bananas': 4}

Q46. What is the purpose of the self keyword when defining or calling methods on an instance of an object?

Explanation: - Try running the example of the Q42 without passing self argument inside the __init__, you’ll understand the reason. You’ll get the error like this __init__() takes 0 positional arguments but 1 was given, this means that something is going inside even if it hasn’t been specified, which is the instance itself.

Q47. What statement about the class methods is true?

Reference
Class methods are methods that are called on the class itself, not on a specific object instance. Therefore, it belongs to a class level, and all class instances share a class method.

Q48. What does it mean for a function to have linear runtime?

Q49. What is the proper way to define a function?

The use of underscores as word separators dates back to the late 1960s. It is particularly associated with C, is found in The C Programming Language (1978), and contrasted with the Pascal case (a type of camel case). However, the convention traditionally had no specific name: the Python programming language style guide refers to it simply as “lowercase_with_underscores”.[2] Within Usenet the term snake_case was first seen in the Rubycommunity in 2004,[3] used by Gavin Kistner, writing: BTW…what _do you call that naming style? snake_case? That’s what I’ll call it until someone corrects me.

reference

Q50. According to the PEP 8 coding style guidelines, how should constant values be named in Python?

Use an uppercase single letter, word, or words. Separate words with underscores to improve readability. Reference

Q51. Describe the functionality of a deque.

Deque or Double Ended Queue is a generalized version of the Queue data structure that allows inserting and deletion at both ends. reference

Q52. What is the correct syntax for creating a variable that is bound to a set?

Q53. What is the correct syntax for defining an __init__() method that takes no parameters?

class __init__(self):
    pass

def __init__():
    pass

class __init__():
    pass

def __init__(self):
    pass

Q54. Which of the following is TRUE About how numeric data would be organized in a Binary Search Tree?

In computer science, a binary search tree (BST), also called an ordered or sorted binary tree, is a rooted binary tree data structure with the key of each internal node being greater than all the keys in the respective node’s left subtree and less than the ones in its right subtree. reference

Q55. Why would you use a decorator?

Decorators allow us to wrap another function to extend the behavior of the wrapped function, without permanently modifying it. reference

Q56. When would you use a for loop?

Reference

Q57. What is the most self-descriptive way to define a function that calculates sales tax on a purchase?

def tax(my_float):
    ''' Calculates the sales tax of a purchase. Takes in a float representing the subtotal as an argument and returns a float representing the sales tax.'''
    pass

def tx(amt):
    ''' Gets the tax on an amount.'''

def sales_tax(amount):
    ''' Calculates the sales tax of a purchase. Takes in a float representing the subtotal as an argument and returns a float representing the sales tax.'''

def calculate_sales_tax(subtotal):
    pass

Q58. What would happen if you did not alter the state of the element that an algorithm is operating on recursively?

explanation

Q59. What is the runtime complexity of searching for an item in a binary search tree?

explanation

Q60. Why would you use mixin?

There are two main situations where mixins are used: You want to provide a lot of optional features for a class. You want to use one particular feature in a lot of different classes. reference explanation

Q61. What is the runtime complexity of adding an item to a stack and removing an item from a stack?

Q62. Which statement accurately describes how items are added to and removed from a stack?

Explanation: Stack uses the last in first out approach.

Q63. What is a base case in a recursive function?

Q64. Why is it considered good practice to open a file from within a Python script by using the with keyword?

It is good practice to use the ‘with’ keyword when dealing with file objects. The advantage is that the file is properly closed after its suite finishes, even if an exception is raised at some point. Using with is also much shorter than writing equivalent try-finally blocks:

example

>>> f = open('workfile', 'w', encoding="utf-8")
>>> with open('workfile', encoding="utf-8") as f:
    read_data = f.read()
# We can check that the file has been automatically closed.
>>> f.closed
True

Reference

Q65. Why would you use a virtual environment?

Q66. What is the correct way to run all the doctests in a given file from the command line?

There is also a command line shortcut for running testmod(). You can instruct the Python interpreter to run the doctest module directly from the standard library and pass the module name(s) on the command line: python -m doctest -v example.py This will import example.py as a standalone module and run testmod() on it. Note that this may not work correctly if the file is part of a package and imports other submodules from that package.
reference
tutorial video

Q67. What is a lambda function ?

Reference

Explanation:

The lambda notation is an anonymous function that can take any number of arguments with only a single expression (i.e., cannot be overloaded). It has been introduced in other programming languages, such as C++ and Java. The lambda notation allows programmers to “bypass” function declaration.

Q68. What is the primary difference between lists and tuples?

Reference

Q69. What does a generator return?

Q70. What is the difference between class attributes and instance attributes?

Q71. What is the correct syntax for creating an instance method?

def get_next_card():
  # method body goes here

def get_next_card(self):
  # method body goes here

def self.get_next_card():
  # method body goes here

def self.get_next_card(self):
  # method body goes here

Q72. What is the correct way to call a function?

Q73. How do you add a comment to an existing Python script?

Reference

Q74. What is the correct syntax for replacing the string apple in the list with the string orange?

my_list = ['kiwi', 'apple', 'banana']

Q75. What will happen if you use a while loop and forget to include logic that eventually causes the while loop to stop?

Q76. Describe the functionality of a queue.

Typical queue definition follows “first-in, first out” (FIFO) where items are enqueued on one-side and dequeued from the other. Reference

Q77. Which choice is the most syntactically correct example of conditional branching?

num_people = 5

if num_people > 10:
    print("There is a lot of people in the pool.")
elif num_people > 4:
    print("There are some people in the pool.")
else:
    print("There is no one in the pool.")

num_people = 5

if num_people > 10:
    print("There is a lot of people in the pool.")
if num_people > 4:
    print("There are some people in the pool.")
else:
    print("There is no one in the pool.")

num_people = 5

if num_people > 10;
    print("There is a lot of people in the pool.")
elif num_people > 4;
    print("There are some people in the pool.")
else;
    print("There is no one in the pool.")

if num_people > 10;
    print("There is a lot of people in the pool.")
if num_people > 4;
    print("There are some people in the pool.")
else;
    print("There is no one in the pool.")

Q78. How does defaultdict work?

defaultdict is a container-like dictionary present in the module collections. The functionality of both dictionaries and defaultdict are almost the same except for the fact that defaultdict never raises a KeyError. It provides a default value for the key that does not exist.

example

# Function to return a default
# values for keys that are not
# present
def def_value():
    return "Not Present"

# Defining the dict
d = defaultdict(def_value)

reference

Q79. What is the correct syntax for adding a key called variety to the fruit_info dictionary that has a value of Red Delicious?

Q80. When would you use a while loop?

Simple Example

i = 1
while i<6:
    print(f"Countdown: {i}")
    i = i + 1

Q81. What is the correct syntax for defining an __init__() method that sets instance-specific attributes upon creation of a new class instance?

def __init__(self, attr1, attr2):
    attr1 = attr1
    attr2 = attr2

def __init__(attr1, attr2):
    attr1 = attr1
    attr2 = attr2

def __init__(self, attr1, attr2):
    self.attr1 = attr1
    self.attr2 = attr2

def __init__(attr1, attr2):
    self.attr1 = attr1
    self.attr2 = attr2

Explanation:: When instantiating a new object from a given class, the __init__() method will take both attr1 and attr2, and set its values to their corresponding object attribute, that’s why the need of using self.attr1 = attr1 instead of attr1 = attr1.

Q82. What would this recursive function print if it is called with no parameters?

def count_recursive(n=1):
    if n > 3:
        return
    print(n)

    count_recursive(n + 1)

1
1
2
2
3
3

3
2
1

3
3
2
2
1
1

1
2
3

Q83. In Python, when using sets, you use _ to calculate the intersection between two sets and _ to calculate the union.

Q84. What will this code fragment return?

import numpy as np
np.ones([1,2,3,4,5])

Reference

Q85. You encounter a FileNotFoundException while using just the filename in the open function. What might be the easiest solution?

Q86. what will this command return?

{x for x in range(100) if x%3 == 0}

reference It is a Set Comprehension because in ‘{}’, curly brackets, so it will return a ‘Set`!

Q87. What does the // operator in Python 3 allow you to do?

Q88. What file is imported to use dates in Python?

Q89. What is the correct syntax for defining a class called Game?

reference here

Q90. What is the correct syntax for calling an instance method on a class named Game?

Q91. What is the output of this code? (NumPy has been imported as np.)?

a = np.array([1,2,3,4])
print(a[[False, True, False, False]])

Q92. Suppose you have a string variable defined as y=”stuff;thing;junk;”. What would be the output from this code?

z = y.split(';')
len(z)

Explanation::

y="stuff;thing;junk"
	len(z) ==> 3

y="stuff;thing;junk;"
	len(z) ==> 4

Q93. What is the output of this code?

num_list = [1,2,3,4,5]
num_list.remove(2)
print(num_list)

Explanation:: .remove() is based on the value of the item, not the index; here, it is removing the item matching “2”. If you wanted to remove an item based on its index, you would use .pop().

num_list = [1,2,3,4,5]

num_list.pop(2)
>>> [1,2,4,5]

num_list.remove(2)
>>> [1,3,4,5]

Q94. Which command will create a list from 10 down to 1? Example:

[10,9,8,7,6,5,4,3,2,1]

Reference

Q95. Which fragment of code will print the same output as this fragment?

import math
print(math.pow(2,10)) # prints 2 elevated to the 10th power

print(2^10)

print(2**10)

y = [x*2 for x in range(1,10)]
print(y)

y = 1
for i in range(1,10):
    y = y * 2
print(y)

Reference

Q96. Elements surrounded by [] are _, {} are _, and () are _.

Reference

Q97. What is the output of this code? (NumPy has been imported as np.)

table = np.array([
    [1,3],
    [2,4]])
print(table.max(axis=1))

Reference

Q98. What will this code print?

number = 3
print(f"The number is {number}")

Reference

Q99. Which syntax correctly creates a variable that is bound to a tuple?

Reference

Q100. Which mode is not a valid way to access a file from within a Python script?

  1. Reference
  2. Reference

Q101. NumPy allows you to multiply two arrays without a for loop. This is an example of _.

Q102. What built-in Python data type can be used as a hash table?

Q103. Which Python function allows you to execute Linux shell commands in Python?

Q104. Suppose you have the following code snippet and want to extract a list with only the letters. Which fragment of code will _not_ achieve that goal?

my_dictionary = {
    'A': 1,
    'B': 2,
    'C': 3,
    'D': 4,
    'E': 5
}

letters = []

for letter in my_dictionary.values():
    letters.append(letter)

Explanation: The first one (the correct option) returns the list of the values (the numbers). The rest of the options return a list of the keys.

Q105. When an array is large, NumPy will not print the entire array when given the built-in print function. What function can you use within NumPy to force it to print the entire array?

Q106. When would you use a try/except block in code?

Reference

Q107. In Python, how can the compiler identify the inner block of a for loop?

Q108. What Python mechanism is best suited for telling a user they are using a deprecated function

Q109. What will be the value of x after running this code?

x = {1,2,3,4,5}
x.add(5)
x.add(6)

Explanation: The .add() method adds the element to the set only if it doesn’t exist.

Q110. How would you access and store all of the keys in this dictionary at once?

fruit_info = {
    'fruit': 'apple',
    'count': 2,
    'price': 3.5
}

Q111. What is wrong with this function definition?

def be_friendly(greet = "How are you!", name):
    pass

Q112. Given that NumPy is imported as np, which choice will return True?

a = np.zeros([3,4])
b = a.copy()
np.array_equal(a,b)

a = np.empty([3,4])
b = np.empty([3,4])
np.array_equal(a,b)

a = np.zeros([3,4])
b = np.zeros([4,3])
np.array_equal(a,b)

a = np.array([1, np.nan])
np.array_equal(a,a)

Q113. How do you add a comment to an existing Python script?

Q114. In this code fragment, what will the values of c and d be equivalent to?

import numpy as np
a = np.array([1,2,3])
b = np.array([4,5,6])
c = a*b
d = np.dot(a,b)

c = [ a[1] * b[1], a[2] * b[2], a[3] * b[3] ]
d = sum(c)

c = a[0] * b[0], a[1] * b[1], a[2] * b[2]

d = [ a[0] * b[0], a[1] * b[1], a[2] * b[2] ]

c = [ a[0] * b[0], a[1] * b[1], a[2] * b[2] ]

d = sum(a) + sum(b)

c = [ a[0] * b[0], a[1] * b[1], a[2] * b[2] ]

d = sum(c)

Q115. What two functions within the NumPy library could you use to solve a system of linear equations?

Explanation: Understanding this answer requires knowledge of linear algebra. Some systems of equations can be solved by the method of diagonalization, which involves finding the eigenvectors and eigenvalues of the system’s matrix and multiplying related matrices.

Q116. What is the correct syntax for creating a variable that is bound to a list?

Reference

Q117. This code provides the _ of the list of numbers.

num_list = [21, 13, 19, 3, 11, 5, 18]
num_list.sort()
num_list[len(num_list) // 2]

Explanation: // is the operator for floor division, which is a normal division operation that returns the largest possible integer, either less than or equal to the normal division result. Here it is used to find the median, which is the value separating the higher half from the lower half of a data sample, by finding the index of the list item in the middle of the list. (This is sufficient for a list with an odd number of items; if the list had an even number of items, you would average the values of the two middle items to find the median value.)

Q118. What are the two main data structures in the Pandas library?

Reference

Q119. Suppose you have a variable named vector of type np.array with 10,000 elements. How can you turn vector into a variable named matrix with dimensions 100x100?

Reference

Q120. Which choice is an immutable data type?

Reference

Q121. What is the output of this code?

def myFunction(country = "France"):
    print(f"Hello, I am from {country}")

myFunction("Spain")
myFunction("")
myFunction()

Hello, I am from Spain
Hello, I am from
Hello, I am from

Hello, I am from France
Hello, I am from France
Hello, I am from France

Hello, I am from Spain
Hello, I am from
Hello, I am from France

Hello, I am from Spain
Hello, I am from France
Hello, I am from France

Q122. Choose the option below for which instance of the class cannot be created.

Reference

Q123. Using Pandas, we load a data set from Kaggle, as structured in the image below. Which command will return the total number of survivors?

Q129

Explanation: The titanic['Survived'] returns a pandas.Series object, which contains the Survived column of the DataFrame. Adding the values of this column (i.e. sum(titanic['Survived'])) returns the total number of survivors since a survivor is represented by a 1 and a loss by 0.

Q124. How would you create a list of tuples matching these lists of characters and actors?

characters = ["Iron Man", "Spider Man", "Captain America"]
actors = ["Downey", "Holland", "Evans"]

# example output : [("IronMan", "Downey"), ("Spider Man", "Holland"), ("Captain America", "Evans")]

Q125. What will this statement return?

{x : x*x for x in range(1,100)}

Q126. Jaccard Similarity is a formula that tells you how similar two sets are. It is defined as the cardinality of the intersection divided by the cardinality of the union. Which choice is an accurate implementation in Python?

Q132

Reference

Q127. Which choice is not a native numerical type in Python?

Q128. What will be the output of this code?

[1,2,3] * 3

Q129. Given a list defined as numbers = [1,2,3,4], what is the value of numbers[-2]?

Q130. Which statement about strings in Python is true?

Q131. What is the correct syntax for defining an _init_() method that takes no parameters?

() - empty parameter. self - refers to all instances within a class. _init_ - a reserved method, AKA a constructor. _init_() - always executed when the class is being initiated.

Q132. Suppose you need to use the sin function from the math library. What is the correct syntax for importing only that function?

Reference

Explanation: The from..import statement allows you to import specific functions/variables from a module instead of importing everything.

Q133. What do you get if you apply numpy.sum() to a list that contains only Boolean values?

Q134. What will this code print?

print("foo" if (256).bit_length() > 8 else "bar")

Q135. If you do not explicitly return a value from a function, what happens?

Q136. It is often the case that the pandas library is used for _ data and NumPy for _ data.

Q137. What do you need to do to install additional packages into Python?

Q138. The image below was created using Matplotlib. It is a distribution plot of a list of integers filled with numbers using the function _ and plotted with _.

Q132

Reference

Q139. In this code fragment, what will be the values of a and b?

import numpy as np

a = np.arange(100)
b = a[50:60:2]

Q140. When using NumPy in Python, how do you check the dimensionality (number and length of dimensions) of an object called my_object?

Q141. Assume you have a non-empty list named mylist and you want to search for a specific value. The minimum number of comparisons will be __ and the maximum number of comparisons will be _?

Explanation: Can use a break statement and the value being searched can be the first element of the list, given that it is non-empty.

Q142. If a function does not have a return statement, what does it return?

Q143. Suppose you want to double-check if two matrices can be multiplied using NumPy for debugging purposes. How would you complete this code fragment by filling in the blanks with the appropriate variables?

import numpy as np

def can_matrices_be_multiplied (matrix1, matrix2):
    rowsMat1, columnsMat1 = matrix1.shape
    rowsMat2, columnsMat2 = matrix2.shape

    if _____ == ______ :
        print("The matrices can be multiplied!")
        return True
    else:
        return False

reference. A matrix can be multiplied by any other matrix that has the same number of rows as the first columns. I.E. A matrix with 2 columns can be multiplied by any matrix with 2 rows

Q144. What is the output of this comprehension?

[(x, x+1) for x in range(1,5)]

Q145. In Python, a class method must have __ as a function decorator, and the first parameter of the method will be a reference to __.

Reference

Q146. Which snippet of code will print My name is Joffrey, son of Robert?

class Father():
    name = 'Robert'

class Person(Father):
    def __init__(self, name):
        self.fathername = super.name
        self.name = name

    def introduce(self):
        print(f"My name is {self.name} son of {self.fathername}")

king = Person("Joffrey")
king.introduce()


class Father():
    name = 'Robert'


class Person(Father):
    def __init__(self, name):
        self.fathername = self.name
        self.name = name

    def introduce(self):
        print(f"My name is {self.name} son of {self.fathername}")


king = Person("Joffrey")
king.introduce()


class Father():
    name = 'Robert'


class Person(Father):
    def __init__(self, name):
        self.name = name

    def introduce(self):
        print(f"My name is {self.name} son of {super.name}")

king = Person("Joffrey")
king.introduce()

class Father():
    name = 'Robert'

class Person(Father):
    def __init__(self, name):
        self.name = name

    def introduce(self):
        print(f"My name is {self.name} son of {base.name}")

king = Person("Joffrey")
king.introduce()

Explanation: In the first, super does not have .name (should be self.name). The third drops Robert, and base is not defined in the 4th.

Q147. What does this code output in the console, assuming defaultdict has already been imported?

animals = {
    'a': ['ant', 'antelope', 'armadillo'],
    'b': ['beetle', 'bear', 'bat'],
    'c': ['cat', 'cougar', 'camel']
}

animals = defaultdict(list, animals)

print(animals['b'])
print(animals['d'])

      ['beetle', 'bear', 'bat']
      []

      ['beetle', 'bear', 'bat']
      # an exception will be thrown

      ['beetle', 'bear', 'bat']
      None

      ['bat', 'bear', 'beetle']
      []

Explanation: Dictionaries usually result in an exception when using the square bracket syntax. Defaultdict here returns a default value dedicated by the first parameter so instead of throwing an exception, they return the default. Note that this needs to be imported as follows: from collections import defaultdict

Reference

Q148. What will this line of code return? (Assume n is already defined as any positive integer value.)

[x*2 for x in range(1,n)]

Reference

Q149. What does this code print in the console?

x = 18

if x > 10:
	if x > 15:
		print('A')
	else:
		print('B')
else:
	print('C')

Q150. What is the maximum length of a Python identifier?

reference No No fixed length is specified but Pep-8 specifies under “Maximum Line Length” to “Limit all lines to a maximum of 79 characters”.

Q151. What will the value of the i variable be when the following loop finishes its execution?

for i in range(5): pass

Q152. f-strings are also called:

Q153. How many CPUs (or cores) will the Python threading library take advantage of simultaneously?

Explanation:: Python threading is restricted to a single CPU at one time. The multiprocessing library will allow you to run code on different processors.

Q154. What will be the value of y in this code?

x = 5
y = 1 + (20 if x < 5 else 30)

Reference

Explanation: If you have only one statement to execute, one for if and one for else, you can put it all on the same line.

x = 5
# This is the same statement expanded to multiple lines
y = 1
if (x < 5):
    y += 20
else:
    y += 30

Q155. The process of pickling in Python includes?

reference
“Pickling” is the process whereby a Python object hierarchy is converted into a byte stream, and “unpickling” is the inverse operation, whereby a byte stream (from a binary file or bytes-like object) is converted back into an object hierarchy.

Q156. What is the output of the following program?

print("codescracker".endswith("er"))

Q157. Is the list mutable in Python?

Q158. What is the output of the following program?

print("programming".center())

reference. The center() method will center align the string, using a specified character (space is the default) as the fill character.
Syntax: string.center(length, character) where length is required!

Q159. Who created the Python programming language?

Q160. Which collection is ordered, changeable, and allows duplicate members?

Q161. What will be printed in the console if you run this code?

x = 1j
print(x**2 == -1)

Explanation: The letter j acts as the imaginary unit in Python, therefore x**2 means j**2 which is equal to -1. The statement x**2 == -1 is evaluated as True.

Q162. What will be printed in the console if you run this code?

print(0xA + 0xB + 0xC)

Explanation: A, B and C are hexadecimal integers with values 10, 11 and 12 respectively, so the sum of A, B and C is 33.

Q163. What will this code output to the screen?

for i in range(5):
    print(i)
else:
    print("Done!")

1
2
3
4
5
Done!

0
1
2
3
4
5
Done!

0
1
2
3
4
Done!

Q164. Which comparison of lists and tuples in Python is correct?

Reference

Q165. Consider the following code snippet that uses decorators to calculate the execution time of the execution_fn function:

import functools
import time

def timer(MISSING_ARG_1):
    @functools.wraps(func)
    def wrapper(*args, **kwargs):
        start_time = time.perf_counter()
        rval = func(*args, **kwargs)
        end_time = time.perf_counter()
        duration = end_time - start_time
        print(f"Executed in {duration:.4f} seconds")
        return MISSING_ARG_2
    return MISSING_ARG_3

@timer
def execution_fn():
    for i in range(3):
        time.sleep(1)

execution_fn()

Which of the following choices are the missing arguments?

MISSING_ARG_1 = wrapper

MISSING_ARG_2 = rval

MISSING_ARG_3 = func

MISSING_ARG_1 = func

MISSING_ARG_2 = rval

MISSING_ARG_3 = wrapper

MISSING_ARG_1 is empty

MISSING_ARG_2 = rval

MISSING_ARG_3 = wrapper

MISSING_ARG_1 is empty

MISSING_ARG_2 = rval

MISSING_ARG_3 = func

Q166. Which of the following statements defines a new object type named Dog in Python?

Q167. To use pipelines in scikit-learn, import from the scikit-learn._ submodule.

reference The correct syntax is actually: from sklearn.pipeline import Pipeline

Q168. You should pass in a value of _ for the axis argument to the Pandas apply method to apply the function to each row.

Q169. Data points in Pyplot are called…

Q170. What does this code print?

a = np.array([[1, 2], [3, 4], [5, 6]])
c = a[(a > 3) & (a < 11)]
print(c)

Q171. Assume m, n, and p are positive integers. In the following comprehension, how many times will the function randint be called?

[ [ [ randint(1,100) for i in range(m) ] for j in range(n) ] for k in range(p) ]

Q172. Suppose you have a class named MyClass which has multiple inheritance and methods with the same name in its ancestors. Which class method could you call to see which method will get priority when invoked?

Explanation: MRO stands for Method Resolution Order. It returns a list of types the class is derived from, in the order they are searched for methods.

Q173. Suppose you have a list of employees described by the code below. You want to assign Alice the same salary as Charlie. Which choice will accomplish that?

employees = {
    'alice':{
        'position':'Lead Developer',
        'salary':1000
    },
    'bob':{
        'position': 'Lead Artist',
        'salary':2000
    },
    'charlie':{
        'position':'cfo',
        'salary':3000
    }
}

Explanation: This is accessing a key in a dictionary nested inside another dictionary. The command employees['alice']['salary'] = employees['charlie']['salary'] assigns the value of the salary key in the dictionary of the employee charlie to the value of the salary key in the dictionary of the employee alice.

Q174. You are given this piece of code. Assume m and n are already defined as some positive integer value. When it completes, how many tuples will my list contain?

mylist = []

for i in range(m):
    for j in range(n):
        mylist.append((i,j))

Explanation: This code will run for m x n times, if you run this code, it will create m x n tuples.

The first loop runs for m times and the inner loop will run for n times. The single iteration of the first loop will only be completed when all of the n iterations of an inner loop are completed. This is the same process for 2nd, and 3rd, … mth iterations for outer loop. Overall, both loops will run m x n times.

Q175. What will this comprehension provide you?

{x : [y for y in range (1, x) if x % y == 0] for x in range (2, 100)}

Q176. What is a common use of Python’s sys library?

Q177. What is the output of 17 % 15 ?

Q178. Let the lists ‘characters’ and ‘actors’ be defined as given. Which of the following lines of code gives the desired output?

characters = ["Iron Man", "Spider Man", "Captain America"]
actors = ["Downey", "Holland", "Evans"]

#Desired output : [("Iron Man", "Downey), ("Spider Man", "Holland"), ("Captain America", "Evans")]

Explanation: zip() is the correct function for this usecase. However, zip() makes a zip type object which is an iterator. Therefore, using list() is necessary to convert the zip object into a list of tuples that can be displayed or accessed directly. The other options have logical errors.

Q179. When is the if __name__ == "__main__": block executed in a Python script?

The if __name__ == "__main__": block is executed when the script is run directly but not when it’s imported as a module in another script. reference

Q180. What will be the output of the following Python code?

def square(x):
	return x * x

numbers = [1, 2, 3, 4, 5]
squared_numbers = map(square, numbers)
result = list(squared_numbers)
print(result)

The code defines a square function to calculate the square of a number. It then uses the map function to apply this function to each element in the numbers list, resulting in a new iterable. Finally, the list constructor is used to convert this iterable into a list. The output will be a list of squared numbers. reference

Q181. Which of the following is not a valid built-in function in Python?

Source

Q182. Which of the following is not a valid Python data type?

Q183. In Python, which function is used to read a line from the console input?

Reference

Q184. What will be the output of the following Python code?

print("Hello {name1} and {name2}".format(name1='foo', name2='bin'))

Q185. What will be the ouput of the following code snippet?

def outer_func(x):
    y = x + 1
    def inner_func():
        return y + x
    return inner_func

x = 10
y = 20
closure_func = outer_func(x)
print(closure_func())

Explanation: When outer_func(10) is called, y is set to 11 within outer_func. The inner_func, which has access to outer_func’s scope, returns y + x. When closure_func() is called, it uses y = 11 (from outer_func) and x = 10 from the global scope, not from the function’s argument. Therefore, closure_func() returns 11 + 10 = 21.

Q186. What is the output of the following Python code?

x = 5
def func():
    x = 10
    print(x)
func()
print(x)

Explanation: The correct answer is 10, 5.

In the given code, the variable x is first defined in the global scope with a value of 5. Inside the func() function, a new local variable x is created and assigned the value of 10. When func() is called, it prints the value of the local x, which is 10.

After the function call, the print statement outside the function refers to the global x, which still has the value of 5.

Therefore, the output is 10, 5.

Q187. What is the output of the following Python code?

def func(a, b=2, c=3):
    print(a, b, c)

func(10)
func(10, 20)
func(10, 20, 30)

Explanation: The correct answer is 10 2 3, 10 20 3, 10 20 30.

In the given code, the func() function has three parameters: a, b, and c. b and c have default values of 2 and 3, respectively.

When func(10) is called, only the first parameter a is provided, so b and c take their default values of 2 and 3, respectively.

When func(10, 20) is called, the first parameter a is 10, and the second parameter b is 20. The third parameter c takes its default value of 3.

When func(10, 20, 30) is called, all three parameters are provided, so a is 10, b is 20, and c is 30.

Therefore, the output is: 10 2 3 10 20 3 10 20 30

Q188. What is the output of the following Python code?

x = [1, 2, 3]
y = x
y.append(4)
print(x)

Explanation: The correct answer is [1, 2, 3, 4].

In Python, assigning y = x does not create a new list; both x and y refer to the same object in memory. So when we call y.append(4), it modifies the original list that both variables point to. Thus, printing x will display the updated list [1, 2, 3, 4].

Q189. What is the output of the following Python code?

def add_item(item, item_list=[]):
    item_list.append(item)
    return item_list

print(add_item(1))
print(add_item(2))
print(add_item(3, []))

Explanation: The correct answer is [1] [1, 2] [3].

In Python, default mutable arguments (like lists) are evaluated only once when the function is defined — not each time it’s called. That means the first two calls to add_item() share the same default list, so it accumulates values [1] and then [1, 2].

However, in the third call add_item(3, []), we pass a new empty list, so it creates a separate list [3].

Q190. Which method is used to implement the len() function for a custom class?

Reference Special Methods

Q191. What will this code output?

def decorator(func):
    def wrapper(*args, **kwargs):
        print("Before function call")
        result = func(*args, **kwargs)
        print("After function call")
        return result
    return wrapper

@decorator
def greet(name):
    print(f"Hello, {name}!")

greet("Alice")

Reference Decorators

Q192. Which statement about Python generators is correct?

Reference Generators

Q193. What is the output of this code?

class Parent:
    def method(self):
        print("Parent method")

class Child(Parent):
    def method(self):
        super().method()
        print("Child method")

obj = Child()
obj.method()

Reference super()

Q194. Which method is used to implement string representation for debugging?

Reference String Representation

Q195. What will this code output?

from functools import lru_cache

@lru_cache(maxsize=None)
def fibonacci(n):
    if n < 2:
        return n
    return fibonacci(n-1) + fibonacci(n-2)

print(fibonacci(10))
print(fibonacci.cache_info())

Reference lru_cache

Q196. Which statement about Python’s with statement is correct?

Reference with statement

Q197. What is the output of this code?

class Counter:
    def __init__(self):
        self.count = 0

    def __call__(self):
        self.count += 1
        return self.count

counter = Counter()
print(counter())
print(counter())
print(counter.count)

Reference Callable Objects

Q198. Which method is used to implement the in operator for a custom class?

Reference Membership Test

Q199. What will this code output?

from dataclasses import dataclass

@dataclass
class Point:
    x: int
    y: int

    def distance_from_origin(self):
        return (self.x ** 2 + self.y ** 2) ** 0.5

p = Point(3, 4)
print(p)
print(p.distance_from_origin())

Reference Dataclasses

Q200. Which statement about Python’s Global Interpreter Lock (GIL) is correct?

Reference GIL

Q201. What is the output of this code?

class Singleton:
    _instance = None

    def __new__(cls):
        if cls._instance is None:
            cls._instance = super().__new__(cls)
        return cls._instance

a = Singleton()
b = Singleton()
print(a is b)
print(id(a) == id(b))

Reference Singleton Pattern

Q202. Which method is used to implement iteration protocol?

Reference Iterator Protocol

Q203. What will this code output?

from enum import Enum

class Color(Enum):
    RED = 1
    GREEN = 2
    BLUE = 3

print(Color.RED)
print(Color.RED.name)
print(Color.RED.value)

Reference Enum

Q204. Which statement about Python’s *args and **kwargs is correct?

Reference Variable Arguments

Q205. What is the output of this code?

class MyClass:
    class_var = 0

    def __init__(self):
        MyClass.class_var += 1
        self.instance_var = MyClass.class_var

a = MyClass()
b = MyClass()
print(a.instance_var, b.instance_var)
print(MyClass.class_var)

Reference Class vs Instance Variables

Q206. Which method is used to implement the + operator for a custom class?

Reference Arithmetic Operations

Q207. What will this code output?

from collections import namedtuple

Person = namedtuple('Person', ['name', 'age', 'city'])
p = Person('Alice', 30, 'New York')
print(p.name)
print(p[1])
print(p._fields)

Reference namedtuple

Q208. Which statement about Python’s lambda functions is correct?

Reference Lambda Expressions

Q209. What is the output of this code?

from functools import partial

def multiply(x, y, z):
    return x * y * z

double = partial(multiply, 2)
result = double(3, 4)
print(result)

Reference functools.partial

Q210. Which method is used to implement comparison operations like <, >, <=, >=?

Reference Rich Comparison Methods

Q211. What will this code output?

class MyContext:
    def __enter__(self):
        print("Entering context")
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        print("Exiting context")
        return False

with MyContext() as ctx:
    print("Inside context")

Reference Context Manager Protocol

Q212. Which statement about Python’s yield from is correct?

Reference yield from

Q213. What is the output of this code?

class Descriptor:
    def __get__(self, obj, objtype=None):
        return "Descriptor value"

    def __set__(self, obj, value):
        print(f"Setting value: {value}")

class MyClass:
    attr = Descriptor()

obj = MyClass()
print(obj.attr)
obj.attr = "new value"
print(obj.attr)

Reference Descriptors

Q214. Which method is used to implement the hash() function for a custom class?

Reference Hash Method

Q215. What will this code output?

from typing import List, Dict

def process_data(items: List[int]) -> Dict[str, int]:
    return {"count": len(items), "sum": sum(items)}

result = process_data([1, 2, 3, 4, 5])
print(result)
print(type(result))

Reference Type Hints

Q216. Which statement about Python’s __slots__ is correct?

Reference slots

Q217. What is the output of this code?

class MRO_A:
    def method(self):
        print("A")

class MRO_B(MRO_A):
    def method(self):
        print("B")
        super().method()

class MRO_C(MRO_A):
    def method(self):
        print("C")
        super().method()

class MRO_D(MRO_B, MRO_C):
    def method(self):
        print("D")
        super().method()

obj = MRO_D()
obj.method()

Reference Method Resolution Order

Q218. Which method is used to implement the del statement for a custom class?

Reference Object Finalization

Q219. What will this code output?

from contextlib import contextmanager

@contextmanager
def my_context():
    print("Setup")
    try:
        yield "resource"
    finally:
        print("Cleanup")

with my_context() as resource:
    print(f"Using {resource}")

Reference contextlib.contextmanager

Q220. Which statement about Python’s property decorator is correct?

Reference Property Decorator

Q221. What is the output of the following code?

class Meta(type):
    def __new__(cls, name, bases, attrs):
        attrs['class_id'] = f"{name}_123"
        return super().__new__(cls, name, bases, attrs)

class MyClass(metaclass=Meta):
    pass

print(MyClass.class_id)

Reference Metaclasses

Q222. Which method is used to create a context manager in Python?

Reference Context Managers

Q223. What will this code output?

import asyncio

async def fetch_data(delay):
    await asyncio.sleep(delay)
    return f"Data after {delay} seconds"

async def main():
    result = await fetch_data(1)
    print(result)

asyncio.run(main())

Reference Asyncio

Q224. Which decorator is used to create a property that can be set?

class Circle:
    def __init__(self, radius):
        self._radius = radius

    @property
    def radius(self):
        return self._radius

    @radius.setter
    def radius(self, value):
        if value < 0:
            raise ValueError("Radius cannot be negative")
        self._radius = value

Reference Property Decorators

Q225. What is the output of this code?

from collections import defaultdict

dd = defaultdict(list)
dd['key1'].append('value1')
dd['key2'].append('value2')
print(len(dd))
print(dd['key3'])
print(len(dd))

Reference defaultdict

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