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。

f=list('123223121321312')
print('成绩表:',f)

f.append('3')
print('增加一个同学的分数后')
print('成绩表:',f)
f.pop(2)
print('删除下标为2的同学的分数后')
print('成绩表:',f)
f[3] = 1
print('修改下标为3的同学的分数')
print('成绩表:',f)


x=f.index('3')
print('查找第一个3分的下标：{}'.format(x))
y=f.count('1')
print('1分的人数有{}个人'.format(y))
s=f.count('3')
print('3分的人数有{}个人'.format(s))

 

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={'赵':95,'钱':86,'孙':75,'李':84,'周':96}
print('学生成绩字典',d)
d['吴']=87
print('增加一个学生')
print(d)
d.pop('孙')
print('删除学生孙')
print(d)
d['吴']=97
print('修改学生吴的成绩')
print(d)
print('查找学生赵的成绩:',d.get('赵'))

 

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('1233332121')
t=tuple('654321123456')
x={'201720':'88','201721':'90','201722':'78'}
s=set('123321332122')
print("列表：",l)
for i in l:
    print(i,end=' ')
print("\n")
print("元组：",t)
for i in t:
    print(i,end=' ')
print("\n")
print("字典：",x)
for i in x:
    print(i,end='\t')
    print(x[i],end='\n')
print("集合：",)
for i in s:
    print(i,end=' ')

4.英文词频统计实例

待分析字符串分解提取单词

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

   1. 排除语法型词汇，代词、冠词、连词

4. 排序list.sort()
5. 输出TOP(10)

6. news='''It's normal for some high calorie food which like fast food brands to poke fun at their competitors,
   howerver, Panera Bread's latest social media campaign isn't cracking jokes.
   It's a call for executives everywhere to put their kiddie meals where their
   mouth is.
   On Wednesday, Panera Bread's founder and CEO, Ron Shaich, launched
   the #KidsMenuChallenge, a social media campaign that challenges other fast food
   executives to spend a week eating the food that's served on their own children's
   menus.'''
   print('新闻：',news)
   
   news=news.lower()
   print('小写：',news)
   
   for i in ',.':
        news=news.replace(i,' ')
   print('符号换成空格：',news)
   
   words=news.split(' ')
   
   dic={}
   keys=set(words)
   exc={"a","to","is","at","the",''}
   for w in exc:
        keys.remove(w)
   for i in keys:
       dic[i]=words.count(i)
   wc=list(dic.items())
   wc.sort(key=lambda x:x[1],reverse=True)
   print('记录次数：')
   for i in range(10):
        print(wc[i])