Chapter 5 Slowniki

Question 1

What does the code for an empty dictionary look like?

Answer 1

{}

Question 2

What does a dictionary value with a key ‘foo’ and a value 42 look like?

Answer 2

{‘foo’: 42}

Question 3

What is the main difference between a dictionary and a list?

Answer 3

The items stored in a dictionary are unordered, while the items in a list are ordered.

Question 4

What happens if you try to access spam[‘foo’] if spam is {‘bar’: 100}?

Answer 4

You get a KeyError error.

Question 5

If a dictionary is stored in spam, what is the difference between the expressions ‘cat’ in spam and ‘cat’ in
spam.keys()?

Answer 5

There is no difference. The in operator checks whether a value exists as a key in the
dictionary.

Question 6

If a dictionary is stored in spam, what is the difference between the expressions ‘cat’ in spam and ‘cat’ in
spam.values()?

Answer 6

‘cat’ in spam checks whether there is a ‘cat’ key in the dictionary, while ‘cat’
in spam.values() checks whether there is a value ‘cat’ for one of the keys in
spam.

Question 7

What is a shortcut for the following code?

if ‘color’ not in spam: spam[‘color’] = ‘black’

Answer 7

spam.setdefault(‘color’, ‘black’)

Question 8

What module and function can be used to “pretty print” dictionary values?

Answer 8

pprint.pprint()