Dictionaries and Sets

Question 1

(Fill-In) _____ can be thought of as unordered collections in which each value is accessed through its corresponding key.

Answer 1

Dictionaries

Question 2

(True/False) Dictionaries may contain duplicate keys.

Answer 2

False. Dictionary keys must be unique. However, multiple keys may have the same value.

Question 3

(Fill-In) Dictionary method _____ returns each key–value pair as a tuple.

Answer 3

items

Question 4

(True/False) Assigning to a nonexistent dictionary key causes an exception.

Answer 4

False. Assigning to a nonexistent key inserts a new key–value pair. This may be what you intend, or it could be a logic error if you incorrectly specify the key.

Question 5

(Fill-In) What does an expression of the following form do when the key is in the dictionary?

dictionaryName[key] = value

Answer 5

Answer: It updates the value associated with the key, replacing the original value.

Question 6

(Fill-In) Dictionary method ____ returns an unordered list of the dictionary’s keys.

Answer 6

keys.

Question 7

(True/False) A view has its own copy of the corresponding data from the dictionary.

Answer 7

False. A view does not have its own copy of the corresponding data from the dictionary. As the dictionary changes, each view updates dynamically.

Question 8

(True/False) The == comparison evaluates to True only if both dictionaries have the
same key–value pairs in the same order.

Answer 8

False. The == comparison evaluates to True if both dictionaries have the same
key–value pairs, regardless of their order.

Question 9

(Fill-In) String method ______ tokenizes a string using the delimiter provided in the method’s string argument.

Answer 9

split.

Question 10

(True/False) Sets are collections of unique mutable and immutable objects.

Answer 10

False. Sets are collections of unique immutable objects

Question 11

(Fill-In) You can create a set from another collection of values by using the built-in ______ function

Answer 11

set.

Question 12

(True/False) Sets may be compared with only the == and != comparison operators.

Answer 12

False. All the comparison operators may be used to compare sets.

Question 13

(Fill-In) A subset is a(n) _____ subset of another set if all the subset’s elements are in the other set and the other set has more elements.

Answer 13

proper.

Question 14

(Fill-In) Two sets are _____ if the sets do not have any common elements.

Answer 14

disjoint.

Question 15

(True/False) Set method pop returns the first element added to the set.

Answer 15

False. Set method pop returns an arbitrary set element.

Question 16

(Fill-In) Set method _____ performs a union operation, modifying the set on which it’s called.

Answer 16

update.

Question 17

(Fill-In) As we toss a coin an increasing number of times, we expect the percentages of heads and tails to become closer to 50% each. This is a manifestation of __________.

Answer 17

the law of large numbers.

Question 18

(Fill-In) A(n) ______ specifies everything that should change during one plot update. Stringing together many of these over time creates the animation effect.

Answer 18

animation frame.

Question 19

(True/False) Generally, displaying fewer frames-per-second yields smoother animation.

Answer 19

False. Generally, displaying more frames-per-second yields smoother animation.

Question 20

(True/False) The actual number of frames-per-second is affected only by the millisecond interval between animation frames.

Answer 20

False. The actual number of frames-per-second also can be affected by the amount of work performed in each frame and the speed of your computer’s processor.

Question 21

(Fill-In) The Matplotlib ______ module’s _____ function dynamically updates
a visualization.

Answer 21

animation, FuncAnimation.

Question 22

(Fill-In) FuncAnimation’s _____ keyword argument enables you to pass custom arguments to the function that’s called once per animation frame.

Answer 22

fargs.