组合数据类型和英文词频统计实例

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。

>>> ls=list('1231323232323131323')
>>> ls
['1', '2', '3', '1', '3', '2', '3', '2', '3', '2', '3', '2', '3', '1', '3', '1', '3', '2', '3']
>>> ls.append('4')
>>> ls.append('5')
>>> ls
['1', '2', '3', '1', '3', '2', '3', '2', '3', '2', '3', '2', '3', '1', '3', '1', '3', '2', '3', '4', '5']
>>> ls.pop()
'5'
>>> ls
['1', '2', '3', '1', '3', '2', '3', '2', '3', '2', '3', '2', '3', '1', '3', '1', '3', '2', '3', '4']

>>> ls.index('3')
2
>>> ls.count('1')
4
>>> ls.count('3')
9
>>>

2.字典实例：建立学生学号成绩字典，做增删改查遍历操作。

>>> d={'01':'95','02':'85','03':'90','04':'92','05':'72','06':'93'}
>>> d.keys()
dict_keys(['01', '02', '03', '04', '05', '06'])
>>> d.values()
dict_values(['95', '85', '90', '92', '72', '93'])
>>> d.get('03','100')
'90'
>>> d['99']='99'
>>> d
{'01': '95', '02': '85', '03': '90', '04': '92', '05': '72', '06': '93', '99': '99'}

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。

>>> l=list('123456665432145')
>>> t=tuple('65432566123333')
>>> d={'01':'刘','02':'张','03':'王','04':'李'}
>>> s=set('123654598777296582')
>>> l
['1', '2', '3', '4', '5', '6', '6', '6', '5', '4', '3', '2', '1', '4', '5']
>>>
>>> t
('6', '5', '4', '3', '2', '5', '6', '6', '1', '2', '3', '3', '3', '3')
>>>
>>> d
{'01': '刘', '02': '张', '03': '王', '04': '李'}
>>>
>>> s
{'8', '2', '7', '9', '1', '3', '6', '5', '4'}
>>>

列表使用方括号，元组使用小括号，字典使用花括号，集合使用[()]；

元组创建很简单，只需要在括号中添加元素，并使用逗号隔开即可，列表则复杂多；

列表、字典、集合能增加、修改、删除，元组不能；

4.英文词频统计实例

new = '''An empty street An empty house
A hole inside heart  all alone and the rooms
Are getting smaller
I wonder how I wonder why
I wonder where they are
The days we had
The songs we sang together
And oh! my love  holding on forever
Reaching for a love
That seems so far
So I say a litter prayer
No my dream will take me there
Where the skies are blue to see you
once again my love
Overseas from coast to coast
Find a place I love the most
Where the fields are green
To see you once again
My love
I Try to read I go to work  laughing with my friends
But I can't stop to keep myself
From thinking
I wonder how I wonder why
I wonder where they are
The days we had
The songs we sang togetther
And oh! my love
I'mholding on forever
Reaching for a love
That seems so far
So I say a litter prayer
No my dream will take me there
Where the skies are blue to see you
once again my love
Overseas from coast to coast
Find a place I love the most
Where the fields are green
To see you once again
To hold you in my arms
To promise my love
To tell you from my heart
You are all I'm thinking of

Reaching for a love
That seems so far
So I say a litter prayer
No my dream will take me there
Where the skies are blue to see you
once again my love
Overseas from coast to coast
Find a place I love the most
Where the fields are green
To see you once again
My love
And hope my dream will take me there
Where the skies are blue to see you
once again my love
Overseas from coast to coast
Find a place I love the most
Where the fields are green
To see you once again
My love'''

new=new.lower()
for i in '.,"':
new=new.replace(i,' ')
word = new.split(' ')
dic ={}
keys = set(word)
for i in keys:
dic[i]=word.count(i)
words = list(dic.items())
words.sort(key= lambda x:x[1],reverse = True)
for i in range(10):
print(word[i])