英文词频统计预备，组合数据类型练习

 实例: 下载一首英文的歌词或文章，将所有,.？！替换为空格，将所有大写转换为小写，统计某几个单词出现的次数，分隔出一个一个的单词。

troye='''We are runnin' so fast
And we never look back
And whatever I lack you make up
We make a really good team
And though not everyone sees
We got this crazy chemistry
Between us
Jump starting your car cause this city's a bore
Buying e-cigarettes at the convenience store
Making new cliches on our own little tour
Let's ride
You don't have to say I love you to say I love you
Forget all the shooting stars and all the silver moons
We've been making shades of purple out of red and blue
Sickeningly sweet like honey don't need money
All I need is you
Hey
All I need is you you
We try staying up late
But we both are light weights
Yeah we get off our face too easy
And we take jokes way too far
And sometimes living's too hard
We're like two halves of one heart
You don't have to say I love you to say I love you
Forget all the shooting stars and all the silver moons
We've been making shades of purple out of red and blue
（Singing with me）
We sickeningly sweet like honey don't need money
All I need is you
All I need is you you
We are not a commercial for anyone else
We go out for coffee and keep it to ourselves
We make little homes of three stars hotels
And i know what's your feeling cause I feel it as well
Hey
You don't have to say I love you to say I love you
Forget all the shooting stars and all the silver moons
Cause we've been making shades of purple out of red and blue
Hey
We sickeningly sweet like honey don't need money
All I need is you
Hey
All I need is you you
You
All I need is you you
say I love you to say I love you
Forget all the shooting stars and all the silver moons
We've been making shades of purple out of red and blue
We sickeningly sweet like honey don't need money
All I need is you
All I need is you you
Thank you guys,thank you so much'''
troye=troye.lower()
for i in ',':
    troye=troye.replace(i,' ')
print(troye.count('you'))
troyes=troye.split(' ')
print(troyes)

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。
全部改为数值型
查询第一个3分的下标
1分的同学有多少个，3分的同学有多少个

grade=list('23654321')
print('初始:',grade)

grade.append('8')
print('增‘8’:',grade)

grade.insert(1,'1')
print('插1:',grade)

grade.pop()
print('删：',grade)

grade[2]='4'
print('改:',grade)

print('第一个3的下标是：',grade.index('3'))
print('1分的同学有:',grade.count('1'))
print('3分的同学有:',grade.count('3'))

for i in range(len(grade)):
    grade[i]=int(grade[i])
print(grade)

 

简要描述列表与元组的异同。

元组一旦初始化就不能改变里面的元素，而列表可以。

列表中的项目应该包括在方括号中，元组在圆括号中
你可以增删改或是搜索列表中的项目。

知识点：

全部大写：str.upper()
全部小写：str.lower()
首字母大写其余小写：str.capitalize()
首字母大写：str.title()
大小写互换：str.swapcase()
print('constellation'.center(46,'-’))
print('开始执行'.center(50,'-'))
print(big.count('big’))
print(big.replace(‘girl’,’boy’))
'https://edu.cnblogs.com/campus/gzcc/14NetworkEngineering/homework/870'.split('/’)
'201406114412'.lstrip(‘20’)
'aaaaaaaaababaaaa'.strip('a')
'aaaaaaaaababaaaa'.rstr

classmates = [‘Michael’, ‘Bob’, ‘Tracy’,‘李三’ ,‘Tracy’,56]
classmates[1],classmates[-1]
classmates[1] = 'Sarah'
len(classmates)，max(classmates), min(classmates)
classmates.sort()
classmates.count(‘Tracy’), classmates.index(‘Tracy’)
classmates.append('Adam’)
classmates.insert(1, 'Jack’)
classmates.pop()
classmates.pop(1)
list(range(5)),list(‘turtle’)