一、

list1=['life','is','short']

list2=['you','need','python']

print(list2[2])

print(list2.index('python'))

list2.append('!')

list1.insert(3,',')

print(list1),print(list2)

list1.extend(list2)

list1.sort()

print(list1)

print(len(list1))

list2[2]="python3"

print(list2)

list1.remove(",")

list2.pop(3)

print(list1),print(list2)

三、

list1=['life','is','short']

list2=['you','need','python']

list3=[1,2,3,4,5,3,4,2,1,5,7,9]

list_set1=set(list1)

print(list_set1)

list1.extend(list2)

list_set2=set(list1)

print(list_set2)

print(len(list_set1),len(list_set2))

list_set1.update(list_set2)

list_set1.remove('python')

list_set1.add('python3')

print(list_set1)