In [ ]:

    

练习4：
voc = input('请输入单词:')
lenth = len(voc)
tail = voc[lenth-1]
lont = voc[lenth-2] + tail
if (tail == 'p') or (tail == 'g') or (tail == 'r'):
    print(voc,'s',sep='')
elif (tail == 's') or (lont == 'sh') or (lont == 'ch') or (tail == 'x'):
    print(voc,'es',sep='')
elif (lont == 'ce') or (lont == 'se') or (lont =='ze') or (lont == 'ge'):
    print(voc,'s',sep='')
elif (tail == 'y'):
    for i in range(lenth-1):
        print(voc[i],sep='',end='')
    print('ies')
    
尝试性练习：
ins = input('您要空行吗?\n'
            '输入要或不要:')
if ins == '要':
    print('来，您的空行\n\n'
          '看到了吧')
else:
    print('不要就给你两个空行\n\n\n'
          '哈哈')

挑战性练习：
num = int(input('您要输入几个整数？'))
print('开始输入这些整数')
m1 = 0
m2 = 0
for i in range(num):
    t = int(input())
    if t > m1:
        m2 = m1
        m1 = t
print(m2)