Python Data Structures - Chapter 9 Quiz

Python lists can store strings and dictionaries can only store words

Python lists are indexed using integers and dictionaries can use strings as indexes

Python lists store multiple values and dictionaries store a single value

Python dictionaries are a collection and lists are not a collection

Question 2

1
point

2. Question 2

What is a term commonly used to describe the Python dictionary feature in other programming languages?

Sequences

Lambdas

Associative arrays

Closures

Question 3

1
point

3. Question 3

What would the following Python code print out?

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stuff = dict()



print(stuff['candy'])

0

-1

candy

The program would fail with a traceback

Question 4

1
point

4. Question 4

What would the following Python code print out?

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stuff = dict()



print(stuff.get('candy',-1))

The program would fail with a traceback

'candy'

0

-1

Question 5

1
point

5. Question 5

(T/F) When you add items to a dictionary they remain in the order in which you added them.

False

True

Question 6

1
point

6. Question 6

What is a common use of Python dictionaries in a program?

Sorting a list of names into alphabetical order

Building a histogram counting the occurrences of various strings in a file

Splitting a line of input into words using a space as a delimiter

Computing an average of a set of numbers

Question 7

1
point

7. Question 7

Which of the following lines of Python is equivalent to the following sequence of statements assuming that counts is a dictionary?

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if key in counts:



    counts[key] = counts[key] + 1



else:



    counts[key] = 1

counts[key] = key + 1

counts[key] = (key in counts) + 1

counts[key] = counts.get(key,0) + 1

counts[key] = (counts[key] * 1) + 1

counts[key] = counts.get(key,-1) + 1

Question 8

1
point

8. Question 8

In the following Python, what does the for loop iterate through?

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x = dict()



...



for y in x :



     ...

It loops through all of the dictionaries in the program

It loops through the integers in the range from zero through the length of the dictionary

It loops through the values in the dictionary

It loops through the keys in the dictionary

Question 9

1
point

9. Question 9

Which method in a dictionary object gives you a list of the values in the dictionary?

values()

items()

keys()

each()

all()

Question 10

1
point

10. Question 10

What is the purpose of the second parameter of the get() method for Python dictionaries?

To provide a default value if the key is not found

The value to retrieve

The key to retrieve

An alternate key to use if the first key cannot be found