ch_5_practice.txt

## 1. What does the code for an empty dictionary look like?
{}


## 2. What does a dictionary value with a key 'foo' and a value 42 look like?

tmp = {'foo': 42}


## 3. What is the main difference between a dictionary and a list?

The elements in a list are ordered, and the elements in a dictionary aren't.
Also, elements in a list must be accessed using numerical indices. Elements in a dictionary are indexed using keys, which can have different data types. 


## 4. What happens if you try to access spam['foo'] if spam is {'bar': 100}?

You will get a KeyError error.


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

There is no difference, the expression " 'cat' in spam " checks whether 'cat' is a key in spam.


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

'cat' in spam checks whether'cat' exists as a key in spam. 'cat' in spam.values() checks whether 'cat' is a value in spam.


## 7. What is a shortcut for the following code?
if 'color' not in spam:
    spam['color'] = 'black'

spam.setdefault('color','black')


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

The module is pprint.
The functions are pprint.pprint() and pprint.pformat().