M03 - Lists

Question 1

List definition and what can be in a list

Answer 1

• Array that contains multiple data items
• Can be data types such as integers, floating-point decimals, strings, and Boolean values as well as lists, tuples, and dictionaries

Question 2

3 Properties of List

Answer 2

1. We can use indexing and slicing to retrieve specific items from the list
2. We can add or remove items from a list, which makes lists dynamic data structure
3. We can change the contents in a list. This means lists are mutable: we can change one or more items in a list to something else.

Question 3

List Syntax

Answer 3

list_variable = [‘Item1’ , ‘Item2’ , ‘Item3’ , ‘Etc….’]

Question 4

Empty List Syntax

Answer 4

empty_list = [ ]

empty_list = list( )

Question 5

3 general rules for indexing

Answer 5

1. Each item in a list has an index that specifies its position in the list
2. Indexing starts at 0. Therefore, the index of the first item is 0, second is 1, third is 2, etc.
3. Because indexing begins at 0, the index of the last item in a list is 1 less than the total number of items in the list

Question 6

Get FIRST indexed item from a list syntax

Answer 6

list_variable[0]

Question 7

Negative Index def + syntax to get LAST item

Answer 7

-Used to identify list item’s position relative to the end of a list

list_variable[-1]

Question 8

Length of a list syntax

Answer 8

len(list_variable)

Question 9

Slicing Format and explanation

Answer 9

list_variable[start : end]

• start is the first index item in slice
• end is index marking end of slice
• expression returns list containing from start UP TO BUT NOT INCLUDING end index value

Question 10

Slice to get index item 3 until the end

Answer 10

list_variable[2:]

Question 11

Slice to get item 5 until the front

Answer 11

list_variable[: 5]

^have to start 1 AFTER whatever you want

Question 12

Add items to a list options

Answer 12

append( )

insert( )

Question 13

append( ) Syntax + where item goes

Answer 13

list_variable.append(‘New Item’)

Goes to end (highest index) of the list

Question 14

insert( ) Syntax + where item goes

Answer 14

list_variable.insert(index , “New Item”)

Goes to designated position in index

Question 15

Discard items from a list options

Answer 15

remove( )

pop( )

Question 16

remove( ) Syntax + how it works

Answer 16

list_variable.remove(“Item”)

Removes 1st (lowest index value) instance of this item, if there are multiples whichever has lowest index is removed

Question 17

pop( ) Syntax + how it works

Answer 17

pop(index)

Removes the indexed value from list and prints it

Question 18

Change an element in a list syntax + what it does

Answer 18

list_variable[index#] = “New Value”

Replaces existing index value with whatever is on the right hand side of the index