组合数据类型练习，英文词频统计实例

1. 列表实例：由字符串创建一个作业评分列表，做增删改查询统计遍历操作。例如，查询第一个3分的下标，统计1分的同学有多少个，3分的同学有多少个等。

>>> gd=list('120123101312313121')
>>> gd
['1', '2', '0', '1', '2', '3', '1', '0', '1', '3', '1', '2', '3', '1', '3', '1', '2', '1']
>>> gd.append('4')
>>> gd
['1', '2', '0', '1', '2', '3', '1', '0', '1', '3', '1', '2', '3', '1', '3', '1', '2', '1', '4']
>>> gd.pop(1)
'2'
>>> gd
['1', '0', '1', '2', '3', '1', '0', '1', '3', '1', '2', '3', '1', '3', '1', '2', '1', '4']
>>> gd.index('3')
4
>>> gd.count('1')
8
>>> gd.count('3')
4

2.字典实例：建立学生学号成绩字典，做增删改查遍历操作。

>>> dic={'张三':'1','李四':'5','王五':'11','林六':'17','何七':'25'}
>>> dic
{'张三': '1', '李四': '5', '王五': '11', '林六': '17', '何七': '25'}
>>> dic['潘二']='50'
>>> dic
{'张三': '1', '李四': '5', '王五': '11', '林六': '17', '何七': '25', '潘二': '50'}
>>> del(dic['潘二'])
>>> dic
{'张三': '1', '李四': '5', '王五': '11', '林六': '17', '何七': '25'}
>>> dic.values()
dict_values(['1', '5', '11', '17', '25'])
>>> dic.keys()
dict_keys(['张三', '李四', '王五', '林六', '何七'])
>>> dic.items()
dict_items([('张三', '1'), ('李四', '5'), ('王五', '11'), ('林六', '17'), ('何七', '25')])
>>> dic.get('李四')
'5'
>>> dic.pop('李四')
'5'
>>> dic
{'张三': '1', '王五': '11', '林六': '17', '何七': '25'}

3.列表，元组，字典，集合的遍历。
总结列表，元组，字典，集合的联系与区别。

a=list('1234456789123456789')
>>> a
['1', '2', '3', '4', '4', '5', '6', '7', '8', '9', '1', '2', '3', '4', '5', '6', '7', '8', '9']
>>> b=tuple('123456789123456789')
>>> b
('1', '2', '3', '4', '5', '6', '7', '8', '9', '1', '2', '3', '4', '5', '6', '7', '8', '9')
>>> c={'qqq':'1','www':'2','eee':'3'}
>>> c
{'qqq': '1', 'www': '2', 'eee': '3'}
>>> d=set('123456789123456789')
>>> d
{'9', '8', '3', '5', '1', '6', '7', '4', '2'}
for i in a:
    print(i,end=' ')

1 2 3 4 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 
for i in b:
    print(i,end=' ')
    
1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 
for i in c:
    print(i,c[i],end=' ')
    
qqq 1 www 2 eee 3 
>>> for i in d:
    print(i,end=' ')

9 8 3 5 1 6 7 4 2

英文词频统计实例

1. 待分析字符串
2. 分解提取单词
   1. 大小写 txt.lower()
   2. 分隔符'.,:;?!-_’
3. 计数字典
4. 排序list.sort()
5. 输出TOP(10)

w='''I need you boo and I see you boo
And the heart's all over the world tonight
Said the heart's all over the world tonight
Hey, little mama, ooh you're a winner
Hey, little mama, yes you're a winner
I'm so glad to be yours
You're a class all your own and
Ooh, little cutie, when you talk to me
I swear the whole world stops
You're my sweetheart
I'm so glad that you're mine
You are one of a kind and
You mean to me
What I mean to you and
Together baby
There is nothing we won't do
'Cause if I got you
I don't need money
I don't need cars
Girl, you're my all
And oh, I'm into you
Girl, no one else would do
'Cause with every kiss and every hug
You make me fall in love
And now I know I can't be the only one
I bet there's hearts all over'''
for i in ",.":
    w=w.replace(i,",")
    for i in w:
        w=w.lower()
words=w.split(" ")

keys=set(words)

dict={}

for i in keys:
    dict[i] = words.count(i)

wc = list(dict.items())
wc.sort(key = lambda x:x[1],reverse=True)

for i in range(10):
    print(wc[i])