组合数据类型练习，英文词频统计实例上

1)字典实例：建立学生学号成绩字典，做增删改查遍历操作。

d={‘小红‘:‘60‘,‘小明‘:‘72‘,‘小东‘:‘98‘,‘小华‘:‘88‘,‘小强‘:‘91‘}

print(d.get(‘小红‘))
d.pop(‘小红‘)
print(d.items())
d[‘小强‘]=81
print(d.items())
for i in d:
    print(i)

结果如下图所示：

2)列表，元组，字典，集合的遍历。

list=[‘1‘,‘2‘,‘3‘,‘4‘,‘5‘,‘6‘]
tu=(‘01‘,‘02‘,‘03‘,‘04‘,‘05‘,‘06‘)
dic={‘01‘:‘88‘,‘02‘:‘99‘,‘03‘:‘77‘,‘04‘:‘86‘,‘05‘:‘96‘,‘06‘:‘98‘}
jihe=set(list)

for i in list:
    print(i)
for i in tu:
    print(i)
for i in dic:
    print(i,dic[i])
for i in jihe:
    print(i)

结果如下图所示：

3)总结列表，元组，字典，集合的联系与区别。

       元组和列表在结构上没有什么区别，唯一的差异在于元组是只读的，不能修改。集合就是我们数学学的集合，没有什么特殊的定义。集合最好的应用是去重。集合没有特殊的表示方法，而是通过一个set函数转换成集合。最后一个是字典，字典存储键值对数据，字典最外面用大括号，每一组用冒号连起来，然后各组用逗号隔开，字典最大的价值是查询，通过键，查找值。

4)英文词频统计实例

1. (1)待分析字符串
2. (2)分解提取单词
3. 大小写 txt.lower()
4. 分隔符‘.,:;?!-_’
5. 单词列表
6. (3)单词计数字典
7. 

   A=‘‘‘The very thought of you  leaving my life
   Broke me down in tears.
   I took for granted all the love
   That you gave to me
   I know that‘s what I feared
   Don‘t go away.
   Every heart beat
   Every moment
   Everything I see is you
   Please forgive me.
   I‘m so sorry
   Don‘t say we‘re through
   Girl I need you  to be by my side
   Girl I need you  to open up my eyes
   Cause without you  where would I be
   Yes I need you
   Come back to me
   A kiss is not a kiss
   Without your lips kissing mine
   You bring me paradise
   I can‘t live if you took your love
   Away from me
   Without you I would die.
   Every second
   Every minute
   Every time I close my eyes.
   I could feel you
   So I want you
   To stay in my life
   Girl I need you  to be by my side
   Girl I need you  to open up my eyes
   Cause without you  where would I be
   Yes I need you
   Come back to me
   Every second,
   Every minute,
   Every time I close my eyes,
   I could feel you.
   So I want you
   To always be mine
   Girl I need you  to be by my side
   Girl I need you  to open up my eyes
   Cause without you  where would I be
   Yes I need you  come back to me
   Girl I need you  to be by my side
   Girl I need you  to open up my eyes
   Cause without you  where would I be
   Yes I need you  come back to me
   Girl I need you  to be by my side
   Girl I need you  to open up my eyes
   Cause without you  where would I be
   Yes I need you  come back to me‘‘‘
   
   A=A.lower()
   for i in ‘,.!‘:
       A=A.replace(i,‘ ‘)
   words=A.split(‘ ‘)
   a=set(words)
   print(words)
   
   dic={}
   for i in a:
       dic[i]=0
   for i in words:
       dic[i]=dic[i]+1
   print(dic)

   

   结果如下图所示：

组合数据类型练习，英文词频统计实例上

原文：http://www.cnblogs.com/Betty18/p/7577105.html