1、字典实例：建立学生学号成绩字典，做增删改查遍历操作。

a={'01':'95','02':'80','03':'98','04':'88','05':'92','06':'85'}

print(a.keys())

print(a.values())

a['07']=89

a['06']=86

a.pop('05')

print(a.get('04'))

print(a)

 

 

2、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('123212131231231')

t = tuple('abcdefghijklmn')

s = set(l)

d = dict(zip([1,2,3,4],[4,3,2,1]))

print(l)

for i in l:

print(i)

for j in t:

print(j)

for k in s:

print(k)

for m in d:

print(m)

列表是可变对象,它支持在原处修改的操作.也可以通过指定的索引和分片获取元素。

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。元组用()表示。元组一旦定义其长度和内容都是固定的。

 集合是一个无序不重复元素集

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。

 

3、英文词频统计实例

A、待分析字符串

B、分解提取单词

a、大小写 txt.lower()

b、分隔符'.,:;?!-_’

c、单词列表

C、单词计数字典

t='''Wake up in the morning feeling like P Diddy

Put my glasses on, I'm out the door

I'm gonna hit this city (Let's go)

Before I leave,

Brush my teeth with a bottle of Jack

Cause when I leave for the night,

I ain't coming back

I'm talking - pedicure on our toes, toes

Trying on all our clothes, clothes

Boys blowing up our phones, phones

Drop-toping, playing our favorite CDs

Pulling up to the parties

Trying to get a little bit tipsy

Don't stop, make it pop

DJ, blow my speakers up

Tonight, Imma fight

Till we see the sunlight

Tick tock, on the clock

But the party don't stop

Woah-oh oh oh

Woah-oh oh oh

Don't stop, make it pop

DJ, blow my speakers up

Tonight, Imma fight

Till we see the sunlight

Tick tock, on the clock

But the party don't stop

Woah-oh oh oh

Woah-oh oh oh

Ain't got a care in world,

But got plenty of beer

Ain't got no money in my pocket,

But I'm already here

And now, the dudes are lining up

Cause they hear we got swagger

But we kick 'em to the curb

unless they look like Mick Jagger

I'm talking about

everybody getting crunk, crunk

Boys trying to touch my junk, junk

Gonna smack him if he getting too drunk, drunk

Now, now - we goin' til they kick us out, out

Or the police shut us down, down

Police shut us down, down

Po-po shut us -

Don't stop, make it pop

DJ, blow my speakers up

Tonight, Imma fight

Till we see the sunlight

Tick tock, on the clock

But the party don't stop

Woah-oh oh oh

Woah-oh oh oh

Don't stop, make it pop

DJ, blow my speakers up

Tonight, Imma fight

Till we see the sunlight

Tick tock, on the clock

But the party don't stop

Woah-oh oh oh

Woah-oh oh oh

DJ, you build me up

You break me down

My heart, it pounds yeah, you got me

With my hands up

You got me now

You gotta that sound yeah, you got me

DJ, you build me up

You break me down

My heart, it pounds yeah, you got me

With my hands up

Put your hands up

Put your hands up

No, the party don't stop until I walk in

Don't stop, make it pop

DJ, blow my speakers up

Tonight, Imma fight

Till we see the sunlight

Tick tock, on the clock

But the party don't stop

Woah-oh oh oh

Woah-oh oh oh

Don't stop, make it pop

DJ, blow my speakers up

Tonight, Imma fight

Till we see the sunlight

Tick tock, on the clock

But the party don't stop

Woah-oh oh oh

Woah-oh oh oh

'''

t=t.lower()

for i in ',.?！':

t=t.replace(i,' ')

t=t.replace('\n',' ')

words=t.split(' ')

s=set(words)

dic={}

lis=[]

value=[]

for i in s:

if(i==' '):

continue

if(i==''):

continue

dic[i]=words.count(i)

lis.append(words.count(i))

vgalue=dic.values()

lis=list(dic.items())

lis.sort(key=lambda x:x[1],reverse=True)

for i in range(10):

print(lis[i])