Problem Solving And Python Programming Set 15 MCQs

Q1 | Suppose d = {“john”:40, “peter”:45}, to delete the entry for “john” what command do we use?

d.delete(“john”:40)

d.delete(“john”)

del d[“john”]

del d(“john”:40)

Q2 | Suppose d = {“john”:40, “peter”:45}. To obtain the number of entries in dictionary which command do we use?

d.size()

len(d)

size(d)

d.len()

Q3 | print(list(d.keys()))

[“john”, “peter”]

[“john”:40, “peter”:45]

(“john”, “peter”)

(“john”:40, “peter”:45)

Q4 | Which of these about a dictionary is false?

the values of a dictionary can be accessed using keys

the keys of a dictionary can be accessed using values

dictionaries aren’t ordered

dictionaries are mutable

Q5 | Which of the following is not a declaration of the dictionary?

{1: ‘a’, 2: ‘b’}

dict([[1,”a”],[2,”b”]]) c) {1,”a”,2”b”}

d) { }

Q6 | ,4))

1

a

4

invalid syntax for get method

Q7 | ,4))

error, invalid syntax

a

5

4

Q8 | ))

{1: ‘a’, 2: ‘b’, 3: ‘c’}

c

{1: 3, 2: 3, 3: 3}

no method called setdefault() exists for dictionary

Q9 | ,"D") print(a)

{1: ‘a’, 2: ‘b’, 3: ‘c’, 4: ‘d’}

none

error

[1,3,6,10]

Q10 | Which of the following isn’t true about dictionary keys?

more than one key isn’t allowed

keys must be immutable

keys must be integers

when duplicate keys encountered, the last assignment wins

Q11 | ) print(a)

{1: 5}

{1: 5, 2: 3}

error, syntax error for pop() method d) {1: 5, 3: 4}

Q12 | ,9))

9

3

too many arguments for pop() method

4

Q13 | Which of the statements about dictionary values if false?

more than one key can have the same value

the values of the dictionary can be accessed as dict[key]

values of a dictionary must be unique

values of a dictionary can be a mixture of letters and numbers

Q14 | If a is a dictionary with some key-value pairs, what does a.popitem() do?

removes an arbitrary element

removes all the key-value pairs

removes the key-value pair for the key given as an argument

invalid method for dictionary

Q15 | )

counter({4: 3, 2: 2, 3: 1})

{3:1}

{4:3}

[(4, 3)]

Q16 | print(a)

true

false

Q17 | ][1])

[2,3,4]

3

2

an exception is thrown

Q18 | ,2,3],"check")

syntax error

{1:”check”,2:”check”,3:”check”}

“check”

{1:none,2:none,3:none}

Q19 | If b is a dictionary, what does any(b) do?

returns true if any key of the dictionary is true

returns false if dictionary is empty

returns true if all keys of the dictionary are true

method any() doesn’t exist for dictionary

Q20 | ]

an exception is thrown since the dictionary is empty

‘ ‘

1

Q21 | ]

1

0

an exception is thrown

‘ ‘

Q22 | ]

4

0

an exception is thrown

7

Q23 | To open a file c:\scores.txt for reading, we use

infile = open(“c:\\scores.txt”, “r”)

infile = open(file = “c:\\scores.txt”, “r”)

Q24 | To open a file c:\scores.txt for writing, we use

outfile = open(“c:\\scores.txt”, “w”)

outfile = open(file = “c:\\scores.txt”, “w”)

Q25 | To open a file c:\scores.txt for appending data, we use

outfile = open(“c:\\scores.txt”, “a”)

outfile = open(“c:\\scores.txt”, “rw”)

outfile = open(file = “c:\\scores.txt”, “w”)