Chapter 7: Lists and Dictionaires

Question 1

container

Answer 1

a construct used to group related values together and contains references to other objects instead of data
Ex. A list

Question 2

list

Answer 2

a container with brackets: []
contains elements

Are Mutable/ Changeable

Question 3

element

Answer 3

a list item

Question 4

index

Answer 4

a position inside of a list

Question 5

method

Answer 5

adds or removes elements to/ from a list

Ex: .append()
.pop()
.remove()

Question 6

.append()

Answer 6

list method is used to add new elements to a list.

Question 7

.pop()

Answer 7

A list method that removes elements from a list

Question 8

.remove()

Answer 8

A list method that removes elements from a list

Question 9

len(list)

Answer 9

Find the length of the list

Question 10

list1 + list2

Answer 10

Produce a new list by concatenating list2 to the end of list1

Question 11

min(list)

Answer 11

Find the element in list with the smallest value. All elements must be of the same type

Question 12

max(list)

Answer 12

Find the element in list with the largest value. All elements must be of the same type.

Question 13

sum(list)

Answer 13

Find the sum of all elements of a list (numbers only)

Question 14

list.index(val)

Answer 14

Find the index of the first element in list whose value matches val.

Question 15

list.count(val)

Answer 15

Count the number of occurrences of the value val in list.

Question 16

set()

Answer 16

an unordered collection of unique elements

Any repeats will only occur once

Are mutable/ changeable

Must enter a list; MUST HAVE BRACKETS!

Question 17

set_literal = {}

Answer 17

Another way of writing a set

Has CURLY Brackets

Question 18

set1.update(set2)

Answer 18

Adds the elements in set2 to set1.

Question 19

set.clear()

Answer 19

Clears all elements from the set

Question 20

set.intersection(set_a, set_b, set_c…)

Answer 20

Returns a new set containing only the elements in common between set and all provided sets.

Question 21

set.union(set_a, set_b, set_c…)

Answer 21

Returns a new set containing all of the unique elements in all sets.

Question 22

set.difference(set_a, set_b, set_c…)

Answer 22

Returns a set containing only the elements of set that are not found in any of the provided sets.

Question 23

set_a.symmetric_difference(set_b)

Answer 23

Returns a set containing only elements that appear in exactly one of set_a or set_b

Question 24

.add() vs .update()

Answer 24

.add()
Adds a single element to a list or set
.update()
Adds multiple elements to a set

Question 25

.remove() vs .pop()

Answer 25

.remove()
deletes a certain VALUE
.pop()
deletes a certain INDEX

Question 26

my_list = [1, 2, 3]

print(my_list)

Answer 26

Creates a list.

[1, 2, 3]

Question 27

my_list = list(‘123’)

print(my_list)

Answer 27

Creates a list

[‘1’, ‘2’, ‘3’]

Question 28

my_list = [1, 2, 3]

print(my_list[1])

Answer 28

Get an element from a list

2

Question 29

my_list[start:end]

Ex:
my_list = [1, 2, 3]
print(my_list[1:3])

Answer 29

Get a new list containing some of another list’s elements.

[2, 3]

Question 30

my_list1 + my_list2

Ex:
my_list = [1, 2] + [3]
print(my_list)

Answer 30

Get a new list with elements of my_list2 added to end of my_list1.

[1, 2, 3]

Question 31

my_list[i] = x

Ex:
my_list = [1, 2, 3]
my_list[2] = 9
print(my_list)

Answer 31

Change the value of the ith element in-place.

[1, 2. 9]

Question 32

del my_list[i]

Ex:
my_list = [1, 2, 3]
del my_list[1]
print(my_list)

Answer 32

Delete an element from a list.

[1, 3]

Question 33

list.append(x)

Ex:
my_list = [5, 8]
my_list.append(16)

Answer 33

Add an item to the end of list.

[5, 8, 16]

Question 34

extend([x])

Ex:
my_list = [5, 8]
my_list.extend([4, 12])

Answer 34

Add all items in [x] to list.

[5, 8, 4, 12]

Question 35

list.insert(i, x)

Ex:
my_list = [5, 8]
my_list.insert(1, 1.7)

Answer 35

Insert x into list before position i.
Basically:
i = index value/ where you want your x
x = what you want to add to the list

[5, 1.7, 8]

Question 36

list.remove(x)

Ex:
my_list = [5, 8, 14]
my_list.remove(8)

Answer 36

Remove first item from list with value x.

[5, 14]

Question 37

list.pop(i)

Ex:
my_list = [5, 8, 14]
val = my_list.pop(0)

Answer 37

Remove and return item at position i in list.

[8, 14]
val is 5

By Default:
i = -1
AKA: the last item/ element

Question 38

list.sort()

Ex:
my_list = [14, 5, 8]
my_list.sort()

Answer 38

Sort the items of list in-place.

[5, 8, 14]

Increasing/ lowest to highest
Alphabetical

Question 39

list.reverse()

Ex:
my_list = [14, 5, 8]
my_list.reverse()

Answer 39

Reverse the elements of list in-place.

[8, 5, 14]

Question 40

list.index(x)

Ex:
my_list = [5, 8, 14]
print(my_list.index(14))

Answer 40

Return index of first item in list with value x.
Basically:
x = the value which you want the index

2

Question 41

list.count(x)

Ex:
my_list = [5, 8, 5, 5, 14]
print(my_list.count(5))

Answer 41

Count the number of times value x is in list.

3

Question 42

in vs not in

Answer 42

operators that can be used in if else statements

in
checks if there is something in something

not in
checks if there is not something in something

Question 43

is vs is not

Answer 43

An identity operator that check whether two operands are bound to a single object

Question 44

for loop

Answer 44

loops over each element in a container one at a time

Syntax:
for in :

Question 45

enumerate()

Answer 45

iterates over a list and provides an iteration counter

Question 46

all(list)

Ex:
print(all([1, 2, 3]))
print(all([0, 1, 2]))

Answer 46

True if every element in list is True (!= 0), or if the list is empty.

True
False

Question 47

any(list)

Ex:
print(any([0, 2]))
print(any([0, 0]))

Answer 47

True if any element in the list is True.

True
False

Question 48

my_list[start:end]

Ex:
my_list = [5, 10, 20]
print(my_list[0:2])

Answer 48

Get a list from start to end (minus 1); end is exclusive

[5, 10]

Question 49

my_list[start:end:stride]

Ex:
my_list = [5, 10, 20, 40, 80]
print(my_list[0:5:3])

Answer 49

Get a list of every stride element from start to end (minus 1)

The stride is how many elements are skipped in between

[5, 40]

Question 50

my_list[start:]

Ex:
my_list = [5, 10, 20, 40, 80]
print(my_list[2:])

Answer 50

Get a list from start to end of the list.

[20, 40, 80]

Question 51

my_list[:end]

Ex:
my_list = [5, 10, 20, 40, 80]
print(my_list[:4])

Answer 51

Get a list from beginning of list to end (minus 1).

[5, 10, 20, 40]

Question 52

my_list[:]

Ex:
my_list = [5, 10, 20, 40, 80]
print(my_list[:])

Answer 52

Get a copy of the list.

[5, 10, 20, 40, 80]

Question 53

dictionary

Answer 53

Like lists but have pairs; kinda how dictionaries have words and a definition assigned to them.

Represented as: dict

Mutable

syntax:
= {}
HAS CURLY BRACKETS

Question 54

key

Answer 54

a term that can be located in a dictionary such as the word “cat” in the English dictionary

Question 55

value

Answer 55

describes some data associated with a key, such as a definition

Question 56

key:value pairs

Ex:
players = {‘Lionel Messi’: 10, ‘Cristiano Ronaldo’: 7}

Answer 56

creates a dictionary called players with two keys: ‘Lionel Messi’ and ‘Cristiano Ronaldo’, associated with the values 10 and 7 (their respective jersey numbers)

Question 57

dict[k] = v:

Answer 57

Adds the new key-value pair k-v, if dict[k] does not already exist.

Updates the existing entry dict[k], if dict[k] already exists.

Question 58

del dict[k]

Answer 58

Deletes the entry dict[k]