高编课后作业------第二周-1

第三章课后习题选做

3-2 问候语： 继续使用练习3-1中的列表， 但不打印每个朋友的姓名， 而为每人打印一条消息。 每条消息都包含相同的问候语， 但抬头为相应朋友的姓名。

name_list = ['Jack','Amy','Kobe']

for name in name_list:
    print(name+' say hello to you.')

3-4 3-5 3-6 3-7  （4个任务连着的

#3-4
people_invited = ['mama','papa','dada','mumu']
print('Invite ',end='')
for per in people_invited:
    print(per+', ',end='')
print('to have dinner.')
#3-5
print('mumu can not come, replaced by jiajia')
people_invited[3] = 'jiajia'
print('Invite ',end='')
for per in people_invited:
    print(per+', ',end='')
print('to have dinner.')
#3-6
print('Find a largger table. So I will invite 3 more people.')
people_invited.insert(0,'new-guest-1')
people_invited.insert(2,'new-guest-2')
people_invited.append('new-guest-3')
print('Invite ',end='')
for per in people_invited:
    print(per+', ',end='')
print('to have dinner.')
#3-7
print("Now I can only invite 2 people.")
while len(people_invited)>2:
    print("Sorry and Byebye " + people_invited.pop())

print(people_invited[0].title()+' and '+people_invited[1]+' are still allowed to come.')
del people_invited[0]
del people_invited[0]
print(people_invited)
print('List is empty now.')

(惊了竟然有人评论

3-8

place = ['Japan', 'America', 'Xinjiang', 'Thailand', 'Russia']
print(place)
print(sorted(place))
print(place)
print(sorted(place,reverse=True))
print(place)
place.reverse()
print(place)
place.reverse()
print(place)
place.sort()
print(place)
place.sort(reverse=True)
print(place)

小发现：

1. insert的位置参数可以大于len，会变成最后一个位置。 但是pop不行。 del 的话更不行了。

2. list在创建的时候可以是 [a, b, c,] 这样子，也就是说c后面的逗号不必刻意去掉，挺舒服的

3.  list.sort()和list.reverse()是没有返回值的