Python Cert

What will happen when you run each of the following code snippets? # Example 1 x = 1 y = 0 z = x%y print(z) # Example 2 x = 1 y = 0 z = x/y print(z) A. A ZeroDivisionError exception will be raised in Example 1, while Example 2 will print 0 to the screen B. A ZeroDivisionError exception will be raised in Example 2, while Example 1 will print 0 to the screen C. A ZeroDivisionError exception will be raised in Example 1 and Example 2 D. A ValueError exception will be raised in Example 1, and a ZeroDivisionError exception will be raised in Example 2 E. A ValueError exception will be raised in Example 2, and a ZeroDivisionError exception will be raised in Example 1

C

What would you insert instead of ??? so that the program prints 1024 to the monitor? Code: lst = [2 ** x for x in range(0, 11)] print(lst???) Expected output: 1024 A. [0] B. [1] C. [-1] D. [1024] E. [:]

C

A complete set of commands is known as: a) Instruction list b) Code laws c) Command-line d) Command list

A

An integer number preceded by an 0x (Zero-x) will be treated as: a) Octal b) Binary c) Hexadecimal d) Decimal

A

How many lines does each of the following code examples output when run separately? # Example 1 for i in range(1, 4, 2): print("*") # Example 2 for i in range(1, 4, 2): print("*", end="") # Example 3 for i in range(1, 4, 2): print("*", end="**") # Example 4 for i in range(1, 4, 2): print("*", end="**") print("***") A. Example 1: two, Example 2: one, Example 3: one, Example 4: one B. Example 1: two, Example 2: one, Example 3: one, Example 4: two C. Example 1: two, Example 2: one, Example 3: two, Example 4: three D. Example 1: one, Example 2: one, Example 3: one, Example 4: two

A

How many stars (*) does the following snippet print? i = 10 while i > 0 : i -= 3 print("*") if i <= 3: break else: print("*") A. three B. two C. one D. The code is erroneous

A

If a list passed into function's argument and modified inside the function: a) Will affect the argument b) Will not affect the argument c) Will give an error d) Will become global by default

A

The meaning of positional parameter is determined by: a) Position b) Name c) Style d) None

A

What is the expected behavior of the following snippet? x = 1 # line 1 def a(x): # line 2 return 2 * x # line 3 x = 2 + a(x) # line 4 print(a(x)) # line 5 It will: A. print 8 B. print 4 C. print 6 D. cause a runtime exception on line 4 E. cause a runtime exception on line 5

A

What is the expected output of the following snippet? dict = { 'a': 1, 'b': 2, 'c': 3 } for item in dict: print(item) A. a b c B. 1 2 3 C. a:1 b:2 c:3 D. 0 1 2 E. The code is erroneous

A

What is the expected output of the following snippet? i = 250 while len(str(i)) > 72: i *= 2 else: i //= 2 print(i) A. 125 B. 250 C. 72 D. 500

A

What is the expected output of the following snippet? lst = ["A", "B", "C", 2, 4] del lst[0:-2] print(lst) A. [2, 4] B. ['C', 2, 4] C. ['B', 'C', 2, 4] D. ['A', 'B']

A

What is the expected output of the following snippet? s = "Hello, Python!" print(s[-14:15]) A. Hello, Python! B. !nohtyP ,olleH C. Hello, Python!Hello, Python! D. !nohtyP ,olleH!nohtyP ,olleH E. The program causes a runtime exception/error F. The result cannot be predicted

A

What will the final value of the Val variable be when the following snippet finishes its execution? Val = 1 Val2 = 0 Val = Val ^ Val2 Val2 = Val ^ Val2 Val = Val ^ Val2 A. 0 B. 1 C. 2 D. 4 E. The code is erroneous

A

If you want to build a string that reads: Peter's sister's name's "Anna" which of the following literals would you use? (Select all that apply) A. "Peter's sister's name's \"Anna\"" B. 'Peter\'s sister\'s name\'s \"Anna\"' C. "Peter's sister's name's "Anna"" D. 'Peter's sister's name's "Anna"'

A,B

Which line can be used instead of the comment to cause the snippet to produce the following expected output? (Select all that apply) Code: z, y, x = 2, 1, 0 x, z = z, y y = y - z # put line here print(x, y, z) Expected output: 0, 1, 2 A. x, y, z = y, z, x B. z, y, x = x, z, y C. y, z, x = x, y, z D. The code is erroneous

A,B

Which of the following are correct statements? a) True + 1 evaluates to 2 b) True and False evaluates to False c) True or False evaluates to False d) 7+ False evaluates to False

A,B

The following code snippet when run f = open("file.txt", "w") f.close() will (select all that apply): A. open the file file.txt in write mode B. delete the file contents if the file file.txt already exists C. leave the file contents unchanged if the file file.txt already exists D. create the file file.txt if it does not exist E. raise the FileNotFoundError exception if the file does not exist

A,B,D

Which of the following is incorrect for a dictionary in Python? a) each key must be unique b) the key should be an immutable object c) the len() function returns the sum of key-value elements in the dictionary d) the len() function returns the numbers of key-value elements in the dictionary

C

Select the true statements: (select all that apply) A. A class definition may have any number of constructors, but their names must be unique B. It is not possible to safely check if an object has a certain attribute C. A class constructor cannot return a value D. __bases__ is a tuple filled with the names of all the direct superclasses E. issubclass(c1, c2) is a function that checks if c1 is an object derived from class c2

C,D

Select the true statements: (select all that apply) A. Inheritance means passing attributes and methods from a superclass to a subclass B. issubclass(class1, class2) is an example of a function that returns True if class2 is a subclass of class1 C. Multiple inheritance means that a class has more than one superclass D. Polymorphism is the situation in which a subclass is able to modify its superclass behavior E. A single inheritance is always more difficult to maintain than a multiple inheritance

A,C,D

Select the true statements: (select all that apply) A. The class keyword marks the beginning of the class definition B. An object cannot contain any references to other objects C. A class may define an object D. A constructor is used to instantiate an object E. An object variable is a variable that is stored separately in every object

A,C,D

You want to access the test.txt file and retrieve each line in it. Which option will you use? (Select all that apply) file = open(test.txt) # insert code here file.close() A. print(file.readlines()) B. print(readlines(file)) C. print(file.readlines(:) D. for l in file: print(l) E. print(file.lines()) F. print(file.read()) G. print(read.file(test.txt))

A,D,F

Octal has the following base: a) 2 b) 8 c) 10 d) 16

B

The following class hierarchy is given. What is the expected output of the code? class A: def a(self): print("A", end='') class B(A): def a(self): print("B", end='') class C(B): def b(self): print("B", end='') a = A() b = B() c = C() a.a() b.a() c.b() A. AB B. ABB C. BA D. BBA E. AAA F. BBB

B

What does the method items() returns in Python Dictionary? a) The method items() returns the lists b) The method items() returns the tuples c) The method items() returns the keys in a list d) The method items() returns the values in a list

B

What is the expected behavior of the following snippet? def gen(): lst = range(5) for i in lst: yield i*i for i in gen(): print(i, end="") A. It will print: <generator object gen at (some hex digits)> B. It will print: 014916 C. It will print: 0 1 4 9 16 D. It will cause a runtime exception/error E. It will print an empty line

B

What is the expected output of the following snippet? lst1 = "12,34" lst2 = lst1.split(',') print(len(lst1) < len(lst2)) A. True B. False C. None D. The program will cause a runtime exception/error

B

What is the result of the following comparison? x = "20" y = "30" print(x > y) A. True B. False C. None D. The comparison causes a runtime exception/error

B

Who created Python? a) Guido ban Rossum b) Guido van Rossum c) Guido the Russian d) Guodo van Rossum

B

If the following snippet is executed and the exception is raised try: print("Hello") raise Exception print(1/0) except Exception as e: print(e) we will see: A. two identical non-empty lines B. two different non-empty lines C. two empty lines D. one non-empty line and one empty line

D

Is there any difference in the error messages displayed once the two newly defined exceptions CriticalError have been raised separately? # Example 1 class CriticalError(Exception): def __init__(self, message='ERROR MESSAGE A'): Exception.__init__(self, message) raise CriticalError raise CriticalError("ERROR MESSAGE B") # Example 2 class CriticalError(Exception): def __init__(self, message='ERROR MESSAGE A'): Exception.__init__(self, message) raise CriticalError("ERROR MESSAGE B") A. No, both errors raised will display the same message: ERROR MESSAGE A B. No, both errors raised will display the same message: ERROR MESSAGE B C. No, both errors raised will display no message D. Yes, the first error raised will display the message ERROR MESSAGE A, while the second ERROR MESSAGE B E. Yes, the first error raised will display no message, while the second ERROR MESSAGE B F. Yes, the first error raised will display no message, while the second ERROR MESSAGE A

D

Python name comes from which of the following? a) Python Café b) Python Forest c) Python snake d) Monty Python's Flying Circus

D

The following expression 2 ** 3 ** 2 ** 1 is: A. invalid B. equal to 16 C. equal to 16.0 D. equal to 512 E. equal to 64 F. equal to 128.0

D

What is the expected behavior of the following snippet? s = 'SPAM' def f(x): return s + 'MAPS' print(f(s)) A. It will print: SPAM B. It will print: MAPS C. It will print: None D. It will print: SPAMMAPS E. It will print: SPAM MAPS F. It will cause a runtime exception/error G. It will print an empty line

D

What is the expected output of the following code? x = 0 try: print(x) print(1 / x) except ZeroDivisionError: print("ERROR MESSAGE") finally: print(x + 1) print(x + 2) The program will print the following to the screen: A. 1 2 B. ERROR MESSAGE 1 2 C. 0 2 D. 0 ERROR MESSAGE 1 2

D

What is true about the __init__.py file? (Select all that apply) A. It cannot be an empty file B. It can execute an initialization code for a package C. It is required to make Python treat a given directory as a Python package directory D. It is required to make Python treat a given directory containing packages as a directory without packages

B,C

What can we deduce from the following snippet? Select the true sentences. (select all that apply) from math import pi as xyz # line 01 print(pi) # line 02 A. The program will print the mathematical constant π = 3.141592..., to available precision B. The program will cause a runtime exception/error C. The program makes an alias for the name pi in the form of xyz D. The original name pi will become inaccessible E. Replacing line 02 with print(xyz) will cause the program to run without errors

B,C,D,E

Select the true statements: (select all that apply) A. Positional arguments are also called keyword arguments B. The order of arguments matters when they are passed positionally C. The order of arguments matters when they are passed by their name D. A function can be called with a mix of positional and keyword arguments

B,D

How many stars (*) will the following snippet send to the console? lst = [[c for c in range(r)] for r in range(3)] for x in lst: for y in x: if y < 2: print('*', end='') A. One B. Two C. Three D. Four E. The program will cause a runtime exception/error

C

What is the value type returned after executing the following snippet? x = 0 y = 2 z = len("Python") x = y > z print(x) A. int B. float C. str D. bool E. NoneType

D

What is the expected behavior of the following snippet? def fun(a, b=0, c=5, d=1): return a ** b ** c print(fun(b=2, a=2, c=3)) It will: A. print 5 B. print 64 C. print 256 D. print 512 E. The code will cause a runtime exception/error

C

What is the expected behavior of the following snippet? x = 5 f = lambda x: 1 + 2 print(f(x)) It will: A. print 5 B. print 8 C. print 3 D. The code will cause a runtime exception/error

C

What is the expected output of the following snippet? a = 0 b = a ** 0 if b < a + 1: c = 1 elif b == 1: c = 2 else: c = 3 print(a + b + c) A. 1 B. 2 C. 3 D. The code is erroneous

C

What is the expected output of the following snippet? s = 'python' for i in range(len(s)): i = s[i].upper() print(s, end="") A. PYTHON B. Python C. python D. P Y T H O N E. P y t h o n F. The code will cause a runtime exception

C

What snippet would you insert in the line indicated below: n = 0 while n < 4: n += 1 # insert your code here to print the following string to the monitor after the loop finishes its execution: 1 2 3 4 A. print(n) B. print(n, sep=" ") C. print(n, end=" ") D. print(n, " ")

C

Which of the following statements are true? (Select all that apply) A. UNICODE is the name of an operating system B. UTF-8 is the name of a data transmission device C. ASCII is an acronym for Automatic Systems of Computer Inner Interoperability D. The Python Language Reference is the official reference manual that describes the syntax and semantics of the Python language E. Python strings are immutable, which means they cannot be sliced F. Python strings are mutable, which means they can be sliced G. Lists and strings in Python can be sliced

D,G

What is the expected output of the following snippet? lst = [i // i for i in range(0,4)] sum = 0 for n in lst: sum += n print(sum) A. 0 B. 3 C. 7 D. 11 E. The program will cause a runtime exception

E

What is the expected behavior of the following code snippet? from random import randint for i in range(10): print(random(1, 5)) A. The program will generate a sequence of ten (pseudo)random integers from 1 to 5 B. The program will generate a sequence of ten (pseudo)random integers from 1 to 4 C. The program will generate a sequence of ten (pseudo)random numbers from 1 to 5 D. The program will generate a sequence of ten (pseudo)random numbers from 1 to 4 E. The result cannot be predicted F. The program will cause a runtime exception/error

F

What is the expected behavior of the following snippet? a = 'hello' # line 1 def x(a,b): # line 2 z = a[0] # line 3 return z # line 4 print(x(a)) # line 5 It will: A. print hello B. print h C. print ello D. cause a runtime exception on line 2 E. cause a runtime exception on line 3 F. cause a runtime exception on line 4 G. cause a runtime exception on line 5

G