empty = []
lst = [21, 32, 43, 54, 65, 76]
print(len(lst))
if (lst[2] == 43):
    print("The 3rd (index: 2) element is 43.")

for i in range(len(lst)):
    print(lst[i])

for i in lst:
    print(i)

if (99 not in lst):
    print("99 is not the element os the list.")

l_a = [1, 3, 5, 7, 9]
l_b = [2, 4]
l_ab = l_a+l_b
print(l_ab)
l_3b = l_b * 3
print(l_3b)

print(l_ab[3:6])

l_a[2] = -8  # Lists are mutable.
print(l_a)
del l_a[3]
print(l_a)

list1 = [1, 2, 3, 4, 5]
list2 = [1, 2, 3, 4, 5]
if(list1 == list2):
    print("'list1' and 'list2' are equivalent.")
if(list1 is not list2):
    print("'list1' and 'list2' are refering to different objects.")
list1[2] = 666
print(list2)

list3 = [1, 2, 3, 4, 5]
list4 = list3
if(list3 == list4):
    print("'list3' and 'list4' are equivalent.")
if(list3 is list4):
    print("'list3' and 'list4' are nicknames refering to the same object.")
list3[2] = 666
print(list4)

list5 = [1, 2, 3, 4, 5]
list6 = list5[:]
if(list5 == list6):
    print("'list5' and 'list6' are equivalent.")
if(list5 is not list6):
    print("'list5' and 'list6' are refering to different objects.")
list5[2] = 666
print(list6)

mylist = ["red", "green", "blue", "green"]
print(mylist)
mylist.append("yellow")
print(mylist)
mylist.insert(2, "black")
print(mylist)
print(mylist.index("yellow"))
print(mylist.count("green"), " 'green' is in the list.")
mylist.reverse()
print(mylist)
mylist.remove("green")
print(mylist)
mylist.sort()
print(mylist)

sentence = "The king drinks gin."
words = sentence.split()
print(words)
glue = "-"
together = glue.join(words)
print(together)
words = sentence.split("in")
print(words)
charcters = list(sentence)
print(charcters)
print("".join(charcters))

matrix = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
print(matrix)
row = matrix[1]
print(row)
element = matrix[1][2]
print(element)