Python Lists
#numbers, booleans, string, list of lists
#matrix is a 2d list
#part 1 make your first list
#list with numbers
#list with strings
list_nums = [1,2,3,4,5]
list_letters = ['a', 'b', 'c', 'd']
list_num_letters = ['a', 3, '5', 6]
list_with_a_list = [[1,4], [3,3], [7,8]]
#part 2 grab elements
#how to print everything
print(list_with_a_list)
#grab the first element from list_nums
list_nums[0]
#grab the 3rd letter from list_letters
list_letters[3]
#negative index
list_letters[-1]
grab multiple elements from listhttps://go.elementor.com/widget-image
list_letters[0:2]
#every 2nd letter
list_letters[::2]
#unpacking
#unpacking
one, two, three, four = list_letters
one, two, *other = list_letters
#part 4 replace elements
list_nums[0] = 8
# list_letters[4] = 'y' # This line caused the error
list_letters[3] = 'y' # Accessing a valid index (the last element)
list_with_a_list[2] = [5,5]
#Part 5 Methods
#number of elements
len(list_letters)
#ascending
list_letters.sort()
print(list_letters)
sorted(list_letters)
#reversed by initial order
list_num_letters.reverse()
print(list_num_letters)
#reverse alphabetical orders
list_nums.sort(reverse=True)
print(list_nums)
#return index
#return index of sometyhing
list_num_letters.index('a')
#add to python list
list_letters.append('z')
print(list_letters)
#add another list using extend metiod
list_letters.extend(['l', 'r'])
print(list_letters)
list_letters_add = ['a', 'b', 'c']
list_letters.extend(list_letters_add)
print(list_letters)
#3rd way to add to list
list_letters = list_letters + ['k', 'z', 'y']
print(list_letters)
#method to add to beginning of list
list_letters.insert(0, 't')
print(list_letters)
list_letters.insert(3, 'q')
print(list_letters)
#remove from python list
#remove original
list_letters.remove('t')
#can only remove 1 item
print(list_letters)
#pop
list_letters.pop(0) #removes 0 by default
print(list_letters)
popped_letter = list_letters.pop(2)
print(popped_letter)
print(list_letters)
#removes the items in the list -> turns the list empty
print(list_num_letters)
list_num_letters.clear()
print(list_num_letters)
#LOOPS
for letter in list_letters:
print(letter)
#enumerate gives index and value
for index, letter in enumerate(list_letters):
print(index, letter)
for index, letter in enumerate(list_letters, start=2):
print(index, letter)
#move index
#memory views
list_letters2 = list_letters
#list_nums2 will change with any list_nums, this isn't a copy
#list_nums2[0] changes list_nums[0]
list_letters2[0] = 'A'
print(list_letters)
print(list_letters2)
#copy Beginning to end, new list
list_letters3=list_letters[:]
list_letters4=list_letters[0:2] #slice option
list_letters5 = list_letters.copy()
list_letters5
list_letters5[0] = "I"
print(list_letters)
print(list_letters5)
#Swapping Elements
temp = list_letters5[1]
list_letters5[1] = list_letters5[3]
list_letters5[3] = temp
print(list_letters5)
#MISC
#print comma seperated
list_str = ' | '.join(list_letters)
print(list_str)
list_letters_from_str = list_str.split(' | ')
print(list_letters_from_str)
#print element multiple times
print(list_letters_from_str[0]*5)
