Solved MCQs on Python

CORE DATATYPES 1. Which of these in not a core datatype? a) Lists b) Dictionary c) Tuples d) Class View Answer Answer:d Explan...

CORE DATATYPES

1. Which of these in not a core datatype?
a) Lists
b) Dictionary
c) Tuples
d) ClassView Answer

Answer:d
Explanation:Class is a user defined datatype.

2. Given a function that does not return any value, What value is thrown by default when executed in shell.
a) int
b) bool
c) void
d) NoneView Answer

Answer:d
Explanation:Python shell throws a NoneType object back.

3. Following set of commands are executed in shell, what will be the output?

1. >>>str="hello"

2. >>>str[:2]

3. >>>

a) he
b) lo
c) olleh
d) helloView Answer

Answer:a
Explanation:We are printing only the 1st two bytes of string and hence the answer is “he”.

4. Which of the following will run without errors(multiple answers possible) ?
a) round(45.8)
b) round(6352.898,2)
c) round()
d) round(7463.123,2,1)View Answer

Answer:a,b
Explanation:Execute help(round) in the shell to get details of the parameters that are passed into the round function.

5. What is the return type of function id ?
a) int
b) float
c) bool
d) dictView Answer

Answer:a
Explanation:Execute help(id) to find out details in python shell.id returns a integer value that is unique.

6. In python we do not specify types,it is directly interpreted by the compiler, so consider the following operation to be performed.

1. >>>x = 13 ? 2

objective is to make sure x has a integer value, select all that apply (python 3.xx)
a) x = 13 // 2
b) x = int(13 / 2)
c) x = 13 / 2
d) x = 13 % 2View Answer

Answer:a,b,d
Explanation:// is integer operation in python 3.0 and int(..) is a type cast operator.

7. What error occurs when you execute?
apple = mango
a) SyntaxError
b) NameError
c) ValueError
d) TypeErrorView Answer

Answer:b
Explanation:Mango is not defined hence name error.

8. Carefully observe the code and give the answer.

1. def example(a):

2.     a = a + '2'

3.      a = a*2

4.     return a

5. >>>example("hello")

a) indentation Error
b) cannot perform mathematical operation on strings
c) hello2
d) hello2hello2View Answer

Answer:a
Explanation:Python codes have to be indented properly.

9. What dataype is the object below ?
L = [1, 23, ‘hello’, 1] a) List
b) dictionary
c) array
d) tupleView Answer

Answer:a
Explanation:List datatype can store any values within it.

10. In order to store values in terms of key and value we use what core datatype.
a) List
b) tuple
c) class
d) dictionaryView Answer

Answer:d
Explanation:Dictionary stores values in terms of keys and values.

11. Which of the following results in a SyntaxError(Multiple answers possible) ?
a) ‘”Once upon a time…”, she said.’
b) “He said, “Yes!””
c) ‘3\’
d) ”’That’s okay”’View Answer

Answer:b,c
Explanation:Carefully look at the colons.

12. The following is displayed by a print function call:

1. tom

2. dick

3. harry

Select all of the function calls that result in this output
a) print(”’tom
\ndick
\nharry”’)
b) print(”’tom
dick
harry”’)
c) print(‘tom\ndick\nharry’)
d) print(‘tom
dick
harry’)View Answer

Answer:b,c
Explanation:The \n adds a new line.

13. What is the average value of the code that is executed below ?

1. >>>grade1 = 80

2. >>>grade2 = 90

3. >>>average = (grade1 + grade2) / 2

a) 85
b) 85.0
c) 95
d) 95.0View Answer

Answer:b
Explanation:Cause a decimal value to appear as output.

14. Select all options that print
hello-how-are-you
a) print(‘hello’, ‘how’, ‘are’, ‘you’)
b) print(‘hello’, ‘how’, ‘are’, ‘you’ + ‘-‘ * 4)
c) print(‘hello-‘ + ‘how-are-you’)
d) print(‘hello’ + ‘-‘ + ‘how’ + ‘-‘ + ‘are’ + ‘-‘ + ‘you’)View Answer

Answer:c,d
Explanation:Execute in the shell.

15. What is the return value of trunc() ?
a) int
b) bool
c) float
d) NoneView Answer

Answer:a
Explanation:Executle help(math.trunc) to get details.

BASIC OPERATORS

1. Which is the correct operator for power(x^y)?
a) X^y
b) X**y
c) X^^y
d) None of the mentionedView Answer

Answer: b
Explanation: In python, power operator is x**y i.e. 2**3=8.

2. Which one of these is floor division?
a) /
b) //
c) %
d) None of the mentionedView Answer

Answer: b
Explanation: When both of the operands are integer then python chops out the fraction part and gives you the round off value, to get the accurate answer use floor division. This is floor division. For ex, 5/2 = 2.5 but both of the operands are integer so answer of this expression in python is 2.To get the 2.5 answer, use floor division.

3. What is the order of precedence in python?
i) Parentheses
ii) Exponential
iii) Division
iv) Multiplication
v) Addition
vi) Subtraction
a) i,ii,iii,iv,v,vi
b) ii,i,iii,iv,v,vi
c) ii,i,iv,iii,v,vi
d) i,ii,iii,iv,vi,vView Answer

Answer: a
Explanation: For order of precedence, just remember this PEDMAS (similar to BODMAS)

4. What is answer of this expression, 22 % 3 is?
a) 7
b) 1
c) 0
d) 5View Answer

Answer: b
Explanation: Modulus operator gives remainder. So, 22%3 gives the remainder, that is, 1.

5. Mathematical operations can be performed on a string. State whether true or false.
a) True
b) FalseView Answer

Answer: b
Explanation: You can’t perform mathematical operation on string even if the string is in the form: ‘1234…’.

6. Operators with the same precedence are evaluated in which manner?
a) Left to Right
b) Right to LeftView Answer

Answer: a
Explanation: None.

7. What is the output of this expression, 3*1**3?
a) 27
b) 9
c) 3
d) 1View Answer

Answer: c
Explanation: First this expression will solve 1**3 because exponential have higher precedence than multiplication, so 1**3 = 1 and 3*1 = 3. Final answer is 3.

8. Which one of the following have the same precedence?
a) Addition and Subtraction
b) Multiplication and Division
c) a and b
d) None of the mentionedView Answer

Answer: c
Explanation: None.

9. The expression Int(x) implies that the variable x is converted to integer. State whether true or false.
a) True
b) FalseView Answer

Answer: a
Explanation: None.

10. Which one of the following have the highest precedence in the expression?
a) Exponential
b) Addition
c) Multiplication
d) ParenthesesView Answer

Answer: d
Explanation: Just remember: PEDMAS, that is, Parenthesis, Exponentiation, Division, Multiplication, Addition, Subtraction. Note that the precedence order of Division and Multiplication is the same. Likewise, the order of Addition and Subtraction is also the same.

VARIABLE NAMES

1. Is Python case sensitive when dealing with identifiers?
a) yes
b) no
c) machine dependent
d) none of the mentionedView Answer

Answer: a
Explanation: Case is always significant.

2. What is the maximum possible length of an identifier?
a) 31 characters
b) 63 characters
c) 79 characters
d) none of the mentionedView Answer

Answer: d
Explanation: Identifiers can be of any length.

3. Which of the following is invalid?
a) _a = 1
b) __a = 1
c) __str__ = 1
d) none of the mentionedView Answer

Answer: d
Explanation: All the statements will execute successfully but at the cost of reduced readability.

4. Which of the following is an invalid variable?
a) my_string_1
b) 1st_string
c) foo
d) _View Answer

Answer: b
Explanation: Variable names should not start with a number.

5. Why are local variable names beginning with an underscore discouraged?
a) they are used to indicate a private variables of a class
b) they confuse the interpreter
c) they are used to indicate global variables
d) they slow down executionView Answer

Answer: a
Explanation: As Python has no concept of private variables, leading underscores are used to indicate variables that must not be accessed from outside the class.

6. Which of the following is not a keyword?
a) eval
b) assert
c) nonlocal
d) passView Answer

Answer: a
Explanation: eval can be used as a variable.

7. All keywords in Python are in
a) lower case
b) UPPER CASE
c) Capitalized
d) noneView Answer

Answer: d
Explanation: True, False and None are capitalized while the others are in lower case.

8. Which of the following is true for variable names in Python?
a) unlimited length
b) all private members must have leading and trailing underscores
c) underscore and ampersand are the only two special characters allowed
d) noneView Answer

Answer: a
Explanation: Variable names can be of any length.

9. Which of the following is an invalid statement?
a) abc = 1,000,000
b) a b c = 1000 2000 3000
c) a,b,c = 1000, 2000, 3000
d) a_b_c = 1,000,000View Answer

Answer: b
Explanation: Spaces are not allowed in variable names.

10. Which of the following cannot be a variable?
a) __init__
b) in
c) it
d) onView Answer

Answer: b
Explanation: in is a keyword.

REGULAR EXPRESSIONS

1. Which module in Python supports regular expressions?
a) re
b) regex
c) pyregex
d) none of the mentionedView Answer

Answer: a
Explanation: re is a part of the standard library and can be imported using: import re.

2. Which of the following creates a pattern object?
a) re.create(str)
b) re.regex(str)
c) re.compile(str)
d) re.assemble(str)View Answer

Answer: c
Explanation: It converts a given string into a pattern object.

3. What does the function re.match do?
a) matches a pattern at the start of the string
b) matches a pattern at any position in the string
c) such a function does not exist
d) none of the mentionedView Answer

Answer: a
Explanation: It will look for the pattern at the beginning and return None if it isn’t found.

4. What does the function re.search do?
a) matches a pattern at the start of the string
b) matches a pattern at any position in the string
c) such a function does not exist
d) none of the mentionedView Answer

Answer: b
Explanation: It will look for the pattern at any position in the string.

5. What is the output of the following?

sentence = 'we are humans'
matched = re.match(r'(.*) (.*?) (.*)', sentence)
print(matched.groups())

a) (‘we’, ‘are’, ‘humans’)
b) (we, are, humans)
c) (‘we’, ‘humans’)
d) ‘we are humans’View Answer

Answer: a
Explanation: This function returns all the subgroups that have been matched.

6. What is the output of the following?

sentence = 'we are humans'
matched = re.match(r'(.*) (.*?) (.*)', sentence)
print(matched.group())

a) (‘we’, ‘are’, ‘humans’)
b) (we, are, humans)
c) (‘we’, ‘humans’)
d) ‘we are humans’View Answer

Answer: d
Explanation: This function returns the entire match.

7. What is the output of the following?

sentence = 'we are humans'
matched = re.match(r'(.*) (.*?) (.*)', sentence)
print(matched.group(2))

a) ‘are’
b) ‘we’
c) ‘humans’
d) ‘we are humans’View Answer

Answer: c
Explanation: This function returns the particular subgroup.

8. What is the output of the following?

sentence = 'horses are fast'
regex = re.compile('(?P<animal>\w+) (?P<verb>\w+) (?P<adjective>\w+)')
matched = re.search(regex, sentence)
print(matched.groupdict())

a) {‘animal’: ‘horses’, ‘verb’: ‘are’, ‘adjective’: ‘fast’}
b) (‘horses’, ‘are’, ‘fast’)
c) ‘horses are fast’
d) ‘are’View Answer

Answer: a
Explanation: This function returns a dictionary that contains all the mathches.

9. What is the output of the following?

sentence = 'horses are fast'
regex = re.compile('(?P<animal>\w+) (?P<verb>\w+) (?P<adjective>\w+)')
matched = re.search(regex, sentence)
print(matched.groups())

a) {‘animal’: ‘horses’, ‘verb’: ‘are’, ‘adjective’: ‘fast’}
b) (‘horses’, ‘are’, ‘fast’)
c) ‘horses are fast’
d) ‘are’View Answer

Answer: b
Explanation: This function returns all the subgroups that have been matched.

10. What is the output of the following?

sentence = 'horses are fast'
regex = re.compile('(?P<animal>\w+) (?P<verb>\w+) (?P<adjective>\w+)')
matched = re.search(regex, sentence)
print(matched.group(2))

a) {‘animal’: ‘horses’, ‘verb’: ‘are’, ‘adjective’: ‘fast’}
b) (‘horses’, ‘are’, ‘fast’)
c) ‘horses are fast’
d) ‘are’View Answer

Answer: d
Explanation: This function returns the particular subgroup.

NUMERIC TYPES

1. What is the output of print 0.1 + 0.2 == 0.3?
a) True
b) False
c) Machine dependent
d) ErrorView Answer

Answer: b
Explanation: Neither of 0.1, 0.2 and 0.3 can be represented accurately in binary. The round off errors from 0.1 and 0.2 accumulate and hence there is a difference of 5.5511e-17 between (0.1 + 0.2) and 0.3.

2. Which of the following is not a complex number?
a) k = 2 + 3j
b) k = complex(2, 3)
c) k = 2 + 3l
d) k = 2 + 3JView Answer

Answer: c
Explanation: l (or L) stands for long.

3. What is the type of inf?
a) Boolean
b) Integer
c) Float
d) ComplexView Answer

Answer: c
Explanation: Infinity is a special case of floating point numbers. It can be obtained by float(‘inf’).

4. What does ~4 evaluate to?
a) -5
b) -4
c) -3
d) +3View Answer

Answer: a
Explanation: ~x is equivalent to -(x+1).

5. What does ~~~~~~5 evaluate to?
a) +5
b) -11
c) +11
d) -5View Answer

Answer: a
Explanation: ~x is equivalent to -(x+1).

6. Which of the following is incorrect?
a) x = 0b101
b) x = 0x4f5
c) x = 19023
d) x = 03964View Answer

Answer: d
Explanation: Numbers starting with a 0 are octal numbers but 9 isn’t allowed in octal numbers.

7. What is the result of cmp(3, 1)?
a) 1
b) 0
c) True
d) FalseView Answer

Answer: a
Explanation: cmp(x, y) returns 1 if x > y, 0 if x == y and -1 if x < y.

8. Which of the following is incorrect?
a) float(‘inf’)
b) float(‘nan’)
c) float(’56’+’78’)
d) float(’12+34′)View Answer

Answer: d
Explanation: ‘+’ cannot be converted to a float.

9. What is the result of round(0.5) – round(-0.5)?
a) 1.0
b) 2.0
c) 0.0
d) None of the mentionedView Answer

Answer: b
Explanation: Python rounds off numbers away from 0 when the number to be rounded off is exactly halfway through. round(0.5) is 1 and round(-0.5) is -1.

10. What does 3 ^ 4 evaluate to?
a) 81
b) 12
c) 0.75
d) 7View Answer

Answer: d
Explanation: ^ is the Binary XOR operator.