Python Lists

From W3

ordered list

list that cannot change order

changeable list

list that may change order or have added/removed items

indexed

set order from 0

list

multiple items in one variable

how to make a list

x\=["a","b","c"]
OR
x\=list(("a","b","c"))

what will len() do to lists

check how many items in the list

T/F: lists may contain any data type

True

T/F: lists may contain multiple data types

True

access "a" in the list
mylist \= list(("a","b","c"))

print(mylist[0])

access "c" in the list using negative index
mylist \= ["a","b","c"]

print(mylist[-1])

slice the list from the 2nd index to the 4th index
mylist \= ["a","b","c","d","e"]

print(mylist[2:5])

Change the 3rd item to "eggs"
grocerylist \= ["milk","sugar","berries"]

grocerylist[2] \= "eggs"

Change all the items after the 3rd item to "apples", "berries"

fruits \= ["peach","plum","pineapple","blueberry","pear"]

fruits [2:] \= ["apples", "berries"]

What will happen to the list below

fruits \= ["melon","orange","peach"]
fruits[1:2] \= "plum","apple","banana"

insert new items, move following items to fit.

fruits \= ["melon","plum","apple","banana","peach"]

what will happen to the list below

fruits \= ["melon","orange","peach"]
fruits[1:3] \= "plum"

replace items in boundary

fruits \= ["melon","plum"]

Remove "nuts" using a string

party \= ["ice cream","sprinkles","nuts"]

party.remove("nuts")

Remove "sprinkles" using "pop"

party \= ["ice cream","sprinkles","nuts"]

party.pop(1)

what will the following lines do

party \= ["ice cream","sprinkles","nuts"]
party.pop()
print(party)

\["ice cream","sprinkles",]

Remove "ice cream" using "delete"

party \= ["ice cream","sprinkles","nuts"]

party.delete[0]

what will the following lines do

party \= ["ice cream","sprinkles","nuts"]
del party
print(party)

Error
\[Deletes list]

what will the following lines do

party \= ["ice cream","sprinkles","nuts"]
party.clear()
print(party)

\[BLANK]
\[Deletes items in list, not list itself]

loop the items in the list
fruits \= ["grapefruit","pineapple","kumquat"]

for x in fruits:
print(x)

loop the items in the list by its length
fruits \= ["grapefruit","pineapple","kumquat"]

for x in range(len(x)):
print(fruits[x])

loop the items in the list using its length
fruits \= ["grapefruit","pineapple","kumquat"]

x \= 0
while x < len(fruits):
print (fruits [x])
x +\= 1

loop the items in the list with a single line

\[print(x) for x in fruits]

for the list "languages" add all asian languages to the following list
languages \= ["japanese","chinese","german","french"]
translator \= ?

translator \= [x for x in languages if "ese" in x]

for the list "ores" add all items EXCLUDING "diamond" using the if condition
ores \= ["iron", "gold", "diamond", "lapis", "emerald"]
inventory \= ?

inventory \= [x for x in ores if x !\= "diamond"]

what is the syntax for list comprehension

newlist \= [ expression for item in iterable if condition \== True]

what will happen in the following list comprehension
inventory \= ["D", "C", "B", "A" , "S"]
myinventory \= [x for x in inventory]

inventory duplicates into myinventory
myinventory \= ["D", "C", "B", "A" , "S"]

iterable

an object capable of returning its members one at a time.

return all the items in the list lowercased
mylist \= ["HAPPY", "sad", "Inspired"]

mylist_1 \= [x.lower() for x in mylist]

return all items in the list as "null"
mylist \= ["player_data", "saves", "memory"]

mylist_1 \= ["null" for x in mylist]

return all items in the list except those containing less than 5 characters to which replace them with "INCREASE_LENGTH"
mylist \= ["superfluous", "goad", "schadenfreude", "ubiquitous", "din"]

mylist_1 \= [x if len(x)\> 5 else "INCREASE_LENGTH" for x in mylist]

Arrange the list alphabetically in ascending order
mylist \= ["apple", "orange", "grapefruit", "peach"]

mylist.sort()

Arrange the list alphabetically in descending order
mylist \= ["apple", "orange", "grapefruit", "peach"]

mylist.sort(reverse \= True)

Arrange the list by character count in ascending order
mylist \= ["chocolate", "Brazil", "dance"]

def mykey(x):
return len(x)

mylist.sort(key \= mykey)

What kind of strings are sorted first

Capitalized strings

sort the list alphabetically in ascending order regardless of capitalization
mylist \= ["apple", "orange", "grapefruit", "peach"]

mylist.sort(key \= str.lower())

arrange the list backwards, disregarding alphabetization
mylist \= ["apple", "orange", "grapefruit", "peach"]

mylist.reverse()

add the string "midnights" to the end of the list
ts \= ["lover", "folklore", "evermore"]

ts.append("midnights")

add the string "1989" as the 2nd item
ts \= ["speak_now","red","reputation"]

ts.insert(1, "1989")

append the items from the former list to the latter
new \= ["btc", "lh"]
existing \= ["lush", "rfascib", "bmamc", "puberty_2"]

existing.extend(new)

what are the issues with list_1 \= list_2 when copying lists

changes to one list will affect the other

copy the list from the former list to the latter
movie \= ["appreciative","nature_lover","romantic"]
personality \= ?

personality \= list(movie)
OR
personality \= movie.copy()

join two list
even_numbers \= [0, 2, 4]
odd_numbers \= [1, 3, 5]

all_numbers \= even_numbers + odd_numbers
OR
even_numbers.extend(odd_numbers)

join two list by appending each item individually from the former list to the latter
even_numbers \= [0, 2, 4]
odd_numbers \= [1, 3, 5]

for x in even_numbers
odd_numbers.append(x)