Dictionaires and Sets

Question 1

In dictionaries _____ does not matter

Answer 1

order

Question 2

To create a dictionary, you place curly brackets ({}) around comma-separated key : value pairs. The simplest dictionary is an empty one, containing no keys or values at all:

Answer 2

> > > empty_dict = {}
empty_dict
{}

Question 3

You can create a dictonary using the function _____

Answer 3

dict()
»> empty_dict = {}
»> empty_dict
{}

Question 4

> > > pythons = {
… ‘Chapman’: ‘Graham’,
… ‘Cleese’: ‘John’,
… ‘Idle’: ‘Eric’,
… ‘Jones’: ‘Terry’,
… ‘Palin’: ‘Michael’,
… }
How to add (Gilliam, Gerry) to this list

Answer 4

> > > pythons[‘Gilliam’] = ‘Gerry’
pythons
{‘Chapman’: ‘Graham’, ‘Cleese’: ‘John’, ‘Idle’: ‘Eric’,
‘Jones’: ‘Terry’, ‘Palin’: ‘Michael’, ‘Gilliam’: ‘Gerry’}

Question 5

Dictinoary Keys must be _____

Answer 5

unique

Question 6

One way to key an item

Answer 6

[key]
»> some_pythons[‘John’]
‘Cleese’

Question 7

Another way to get an item

Answer 7

get()
»> some_pythons.get(‘John’)
‘Cleese’

Question 8

How to get all the key in a dictionary

Answer 8

keys()

Question 9

How to get all the values in a dictionary

Answer 9

values()

Question 10

How to get all the key-value pairs from dictonary

Answer 10

items()
»> list( signals.items() )
[(‘green’, ‘go’), (‘yellow’, ‘go faster’), (‘red’, ‘smile for the camera’)]

Question 11

You can use the ____ funcrion to copy the keys and values from one dictonary to another

Answer 11

update()

Question 12

Delte an item by key with ___

Answer 12

del
»> del pythons[‘Marx’]

Question 13

If you give ____ a key and it exists in the dictionary, it returns the matching value and deletes the key-value pair. If it doesn’t exist, it raises an exception:

Answer 13

pop()

Question 14

How to delete all item

Answer 14

clear()

Question 15

Test for a key with ___

Answer 15

in

Question 16

Dictionaries can be compared with the simple comparison operators ___, ____

Answer 16

==, !=

Question 17

A set is like a dictionary wth values thrown away, leaving only ___

Answer 17

keys

Question 18

Create an empty set

Answer 18

> > > empty_set = set()

Question 19

Function that you can use to create a set from a list, strnig, tuple, or dictionary (discarding any duplciate values)

Answer 19

set()
»> set( ‘letters’ )
{‘l’, ‘r’, ‘s’, ‘t’, ‘e’}

Question 20

Getting the length of a set

Answer 20

len()

Question 21

How to add item to set

Answer 21

add()

Question 22

How to delete an item in set

Answer 22

remove()

Question 23

Intersection operator

Answer 23

&

Question 24

The result of the & operator is a set that contains ____ of the items that appear in both lists that you compare. If neither of those ingredients were in contents, the & returns an empty set, which is considered ___.

Answer 24

all, False

Question 25

You can also use ____ for intersection of sets

Answer 25

intersection()

Question 26

Union function for sets

Answer 26

union()

Question 27

Memebers of first set but no in second set

Answer 27

difference()

Question 28

Check if a set is a ubset set of another set

Answer 28

issubset()

Question 29

Check if all members of the second set are also in the first

Answer 29

issuperset()

Question 30

____ _______ is a way to create lists using a concise syntax. It allows us to generate a new list by applying an expression to each item in an existing iterable (such as a list or range)

Answer 30

List Comprehesion

Question 31

a = [2,3,4,5] res = [val ** 2 for val in a] print(res) What does this code do

Answer 31

[4, 9, 16, 25]

Question 32

a = [1, 2, 3, 4, 5] res = [val for val in a if val % 2 == 0] print(res) What is the list?

Answer 32

[2, 4]

Question 33

Creates a list of numbers from 0 to 9 a = [i for i in range(10)] print(a)

Answer 33

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

Question 34

mat = [[1, 2, 3], [4, 5, 6], [7, 8, 9]] res = [val for row in mat for val in row] print(res)

Answer 34

[1, 2, 3, 4, 5, 6, 7, 8, 9]