Sequences: Lists and Tuples

Question 1

(Fill-In) Python’s string and tuple sequences are _______—they cannot be modified.

Answer 1

immutable.

Question 2

(True/False) The + operator’s sequence operands may be of any sequence type.

Answer 2

False. The + operator’s operand sequences must have the same type; otherwise, a TypeError occurs.

Question 3

(True/False) A += augmented assignment statement may not be used with strings and tuples, because they’re immutable.

Answer 3

False. A += augmented assignment statement also may be used with strings and tuples, even though they’re immutable. The result is a new string or tuple, respectively.

Question 4

(True/False) Tuples can contain only immutable objects.

Answer 4

False. Even though a tuple is immutable, its elements can be mutable objects, such as lists.

Question 5

(Fill-In) A sequence’s elements can be ________ by assigning the sequence to a comma-separated list of variables.

Answer 5

unpacked

Question 6

(True/False) The following expression causes an error:

’-‘ * 10

Answer 6

False: In this context, the multiplication operator (*) repeats the string (‘-‘) 10 times.

Question 7

(True/False) Slice operations that modify a sequence work identically for lists, tuples and strings

Answer 7

False. Slice operations that do not modify a sequence work identically for lists, tuples and strings

Question 8

(Fill-In) Assume you have a list called names. The slice expression ______ creates a new list with the elements of names in reverse order.

Answer 8

names[::-1]

Question 9

(True/False) You cannot modify a list’s contents when you pass it to a function.

Answer 9

False. When you pass a list (a mutable object) to a function, the function receives a reference to the original list object and can use that reference to modify the original list’s contents

Question 10

(True/False) Tuples can contain lists and other mutable objects. Those mutable objects can be modified when a tuple is passed to a function.

Answer 10

True

Question 11

(Fill-In) To sort a list in descending order, call list method sort with the optional keyword argument ______ set to True.

Answer 11

reverse.

Question 12

(True/False) All sequences provide a sort method.

Answer 12

False. Immutable sequences like tuples and strings do not provide a sort method. However, you can sort any sequence without modifying it by using built-in function sorted, which returns a new list containing the sorted elements of its argument sequence.

Question 13

(Fill-In) The _______ operator can be used to extend a list with copies of itself.

Answer 13

*=

Question 14

(Fill-In) Operators ______ and ______ determine whether a sequence contains or does not contain a value, respectively.

Answer 14

in, not in

Question 15

(Fill-In) To add all the elements of a sequence to the end of a list, use list method _______, which is equivalent to using +=.

Answer 15

extend

Question 16

(Fill-In) For a list numbers, calling method ________ is equivalent to numbers[:] = [].

Answer 16

clear.

Question 17

(Fill-In) You can simulate a stack with a list, using methods ______ and _____ to add and remove elements, respectively, only at the end of the list.

Answer 17

append, pop

Question 18

Fill-In) To prevent an IndexError when calling pop on a list, first ensure that _______.

Answer 18

the list’s length is greater than 0.

Question 19

(Fill-In) A list comprehension’s ______ clause iterates over the specified sequence.

Answer 19

for.

Question 20

(Fill-In) A list comprehension’s ______ clause filters sequence elements to select only those that match a condition.

Answer 20

if.

Question 21

(Fill-In) A generator expression is ______—it produces values on demand

Answer 21

lazy.

Question 22

(Fill-In) _______, _______ and _______ are common operations used in functional-style programming

Answer 22

Filter, map, reduce.

Question 23

(Fill-In) A(n) _______ processes a sequence’s elements into a single value, such as their count, total or average.

Answer 23

reduction

Question 24

(True/False) The letter ‘V’ “comes after” the letter ‘g’ in the alphabet, so the comparison ‘Violet’ < ‘green’ yields False

Answer 24

False. Strings are compared by their characters’ underlying numerical values. Lowercase letters have higher numerical values than uppercase. So, the comparison is True.

Question 25

(Fill-In) Built-in function ______ returns an iterator that enables you to iterate over a sequence’s values backward.

Answer 25

reversed.

Question 26

(Fill-In) In a two-dimensional list, the first index by convention identifies the ______ of an element and the second index identifies ______ the of an element.

Answer 26

row, column

Question 27

(Fill-In) The ________ format specifier indicates that a number should be displayed with thousands separators.

Answer 27

comma (,)

Question 28

(Fill-In) A Matplotlib ______ object manages the content that appears in a Matplotlib window

Answer 28

Axes

Question 29

(Fill-In) The Seaborn function ____ displays data as a bar chart.

Answer 29

barplot

Question 30

(Fill-In) The Matplotlib function ______ displays a plot window from a script.

Answer 30

show.