成绩表增删改查遍历操作classmate = list("123321123321")
print(classmate)classmate.append('3')
print(classmate[-1])classmate.pop()
print(classmate[-1])classmate[-1] = 2
print(classmate[-1])print(classmate.index('3'))
print(classmate.count('1'))
print(classmate.count('3'))

================ RESTART: C:/Users/Administrator/Desktop/1.py ================
['1', '2', '3', '3', '2', '1', '1', '2', '3', '3', '2', '1']
3
1
2
2
3
4
>>> 

建立学生学号成绩字典

score = {10:'41',20:'64',30:'71',40:'81',50:'91'}
print(score)
score[6] = '90'
print(score)
score.pop(6)
print(score)for i in score:print("{:>2} : {:<2}".format(i,score.get(i)))

================ RESTART: C:/Users/Administrator/Desktop/1.py ================
{10: '41', 20: '64', 30: '71', 40: '81', 50: '91'}
{10: '41', 20: '64', 30: '71', 40: '81', 50: '91', 6: '90'}
{10: '41', 20: '64', 30: '71', 40: '81', 50: '91'}
10 : 41
20 : 64
30 : 71
40 : 81
50 : 91
>>>

列表，元组，字典，集合。ls=list("4613125646")
tu=tuple("4613125646")
se=set("4613125646")
d={'阿一':93,'阿二':74,'阿三':45,'阿四':66}
print("列表：",ls)
for i in ls:print(i,end=' ')
print("\n")
print("元组：",tu)
for i in tu:print(i,end=' ')
print("\n")
print("集合：",se)
for i in se:print(i,end=' ')
print("\n")
print("字典：",d)
for i in d:print(i,end='\t')print(d[i],end='\n')

================ RESTART: C:/Users/Administrator/Desktop/1.py ================
列表： ['4', '6', '1', '3', '1', '2', '5', '6', '4', '6']
4 6 1 3 1 2 5 6 4 6 元组： ('4', '6', '1', '3', '1', '2', '5', '6', '4', '6')
4 6 1 3 1 2 5 6 4 6 集合： {'4', '2', '6', '3', '5', '1'}
4 2 6 3 5 1 字典： {'阿一': 93, '阿二': 74, '阿三': 45, '阿四': 66}
阿一  93
阿二  74
阿三  45
阿四  66

歌词统计 song = '''Vincent,Don McLean. Starry starry night paint your palette blue and grey look out on a summer\'s day with eyes that know the darkness in my soul. Shadows on the hills sketch the trees and the daffodils catch the breeze and the winter chills in colors on the snowy linen land. And now I understand what you tried to say to me and how you suffered for your sanity and how you tried to set them free. They would not listen they did not know how perhaps they\'ll listen now. Starry starry night flaming flowers that brightly blaze swirling clouds in violet haze reflect in Vincent\'s eyes of China blue. Colors changing hue morning fields of amber grain weathered faces lined in pain are smoothed beneath the artist\'s loving hand. And now I understand what you tried to say to me and how you suffered for your sanity and how you tried to set them free. They would not listen they did not know how perhaps they\'ll listen now. For they could not love you but still your love was true and when no hope was left in sight on that starry starry night. You took your life as lovers often do, But I could have told you Vincent this world was never meant for one as beautiful as you. Starry starry night portraits hung in empty halls frameless heads on nameless walls with eyes that watch the world and can\'t forget. Like the stranger that you\'ve met the ragged men in ragged clothes the silver thorn of bloddy rose lie crushed and broken on the virgin snow. And now I think I know what you tried to say to me and how you suffered for your sanity and how you tried to set them free. They would not listen they\'re not listening still perhaps they never will.'''song = song.lower()
for i in '?!,.\'\n':song = song.replace(i,' ')
words = song.split(' ')dic={}
keys = set(words)
for i in keys:dic[i]=words.count(i)c = list(dic.items())
c.sort(key=lambda x:x[1],reverse=True)for i in range(10):print(c[i])

================ RESTART: C:/Users/Administrator/Desktop/1.py ================
('', 112)
('and', 15)
('you', 14)
('the', 13)
('they', 10)
('to', 9)
('starry', 8)
('how', 8)
('in', 8)
('not', 7)
>>>