Strings and dictionaries

Question 1

Each element that is stored in a dictionary has two parts: ___

a list and a value.
a list and an index.
a key and a value.
a list and a class.

Answer 1

a key and a value

Question 2

A dictionary can include the same value several times but cannot include the same key several times.

TRUE
FALSE

Answer 2

TRUE

Question 3

You cannot use a for loop to iterate over the characters in a string.

TRUE
FALSE

Answer 3

FALSE

Question 4

The values that are stored in a single dictionary can be of different types.

TRUE
FALSE

Answer 4

TRUE

Question 5

The elements in a dictionary are stored in ascending order, by the keys of the key-value pairs.

FALSE

Answer 5

FALSE

Question 6

What will be assigned to the variable z after the following code executes?

x = '123 Panorama Ave'
z = x[4:]

’ Ave’
‘123 ‘
‘Panorama’
‘Panorama Ave’

Answer 6

‘Panorama Ave’

Question 7

To test if the user input contains only alphabetical letters, you can use the ________ string method.

isalpha()
ascii()
strip()
isletter()

Answer 7

isalpha()

Question 8

The ________ method returns all the dictionary key-value pairs in the form of a sequence of tuples.

items()
values()
tuples()
sequence()

Answer 8

items()

Question 9

If you try to retrieve a value from a dictionary using a nonexistent key, a KeyError exception is raised.

TRUE
FALSE

Answer 9

TRUE

Question 10

Dictionaries are immutable objects.

TRUE
FALSE

Answer 10

FALSE

Question 11

In slicing, if the end index specifies a position beyond the end of the string, Python will use the length of the string instead.

TRUE
FALSE

Answer 11

TRUE

Question 12

The following expression is valid: string[0] = ‘k’

TRUE
FALSE

Answer 12

FALSE

Question 13

If a whole paragraph is included in a single string, the split() method can be used to obtain a list of the sentences in the paragraph.

TRUE
FALSE

Answer 13

TRUE

Question 14

A dictionary can include the same value several times but cannot include the same key several times.

TRUE
FALSE

Answer 14

TRUE

Question 15

If you try to retrieve a value from a dictionary using a nonexistent key, an IndexError exception is raised.

TRUE
FALSE

Answer 15

FALSE

Question 16

What are the valid indexes for the string ‘New York’?

0 through 8
-1 through 6
-1 through -8
0 through 7

Answer 16

0 through 7

-1 through -8

Question 17

What will be displayed after the following code executes?

mystr = ‘yes’
yourstr = ‘no’
mystr += yourstr * 2
print(mystr)

yesnono
yes + no * 2
yes + no yes + no
yesnoyesno

Answer 17

yesnono

Question 18

What will be assigned to the variable s_string after the following code executes?

special = '1357 Country Ln.'
s_string = special[ :4]

'7'
'7 Country Ln.'
'1357'
5

Answer 18

‘1357’

Question 19

What will be assigned to the string variable pattern after the following code executes?

i = 3
pattern = 'z' * (5 * i)

Nothing; this code is invalid
'zzzzz'
'z * 15'
'zzzzzzzzzzzzzzz'

Answer 19

‘zzzzzzzzzzzzzzz’

Question 20

Which method would you use to determine whether a certain substring is present in a string?

find(substring)
replace(string, substring)
endswith(substring)
startswith(substring)

Answer 20

find(substring)

Question 21

What list will be referenced by the variable list_strip after the following code executes?

my_string = '03/07/2018'
list_strip = my_string.split('/')

['3', '7', '2018']
['03', '07', '2018']
['3', '/', '7', '/', '2018']
['03', '/', '07', '/', '2018']

Answer 21

[‘03’, ‘07’, ‘2018’]

Question 22

What is the correct structure to create a dictionary of months where each month will be accessed by its month number (for example, January is month 1, April is month 4)?

{ 1, 2,... 12 : 'January', 'February',... 'December' }
{ 1 : 'January', 2 : 'February', ... 12 : 'December' }
{ 1 ; 'January', 2 ; 'February', ... 12 ; 'December'}
[ '1' : 'January', '2' : 'February', ... '12' : 'December' ]

Answer 22

{ 1 : ‘January’, 2 : ‘February’, … 12 : ‘December’ }

Question 23

What will be the result of the following code?

ages = {'Aaron' : 6, 'Kelly' : 3, 'Abigail' : 1 }
value = ages['Brianna']

KeyError
False
0
-1

Answer 23

KeyError

Question 24

Which would you use to get the number of elements in a dictionary?

sizeof
len
length
size

Answer 24

len

Question 25

In order to avoid KeyError exceptions, you can check whether a key is in the dictionary using the __________ operator.

is in
is not in
included
in

Answer 25

in