作業(yè)2：

s ='this is a book'

i = s.replace('book','apple')

print(i)

j = s.startswith('this')

print(j)

l = s.endswith('book')

print(j)

a ='this is a book@'

b = a.rstrip('@')

print(b)

作業(yè)3：

li = [2,5,6,4,9,10,23]

li.sort(reverse=True)

print(li)

li2 = [2,5,6,4,9,10,23]

print(li2[-1:-4:-2]+li2[-6::-1])

作業(yè)4：

j =input("請輸入字符串：")

if len(j) >=3:

print(j+'ing')

if j.endswith('ing'):

print(j+'ly')

elif len(j) <3:

print(j)