字符串练习

字符串练习：

http://news.gzcc.cn/html/2017/xiaoyuanxinwen_1027/8443.html

取得校园新闻的编号

addr = 'http://news.gzcc.cn/html/2018/xiaoyuanxinwen_0308/9005.html'
print(addr[-14:-5])
print(addr.rstrip('.html')[-9:])
print(addr.rstrip('.html').split('_')[1])

 

https://docs.python.org/3/library/turtle.html

产生python文档的网址

site1 = 'https://docs.python.org/3/library/'
site2 = '.html'
want = ['turtle', 'index', 'string']
for i in want:
    print('https://docs.python.org/3/library/{}.html'.format(i))
    print(site1+i+site2)

 

 

http://news.gzcc.cn/html/xiaoyuanxinwen/4.html

产生校园新闻的一系列新闻页网址 

for i in range(2, 231):
    s = 'http://news.gzcc.cn/html/xiaoyuanxinwen/{}.html'.format(i)
    print(s)

 

练习字符串内建函数：strip,lstrip,rstrip,split,count

用函数得到校园新闻编号

addr = 'http://news.gzcc.cn/html/2018/xiaoyuanxinwen_0308/9005.html'
print(addr.rstrip('.html')[-9:])
print(addr.rstrip('.html').split('_')[1])

 

用函数统计一歌词中单词出现的次数

歌曲《Welcome to New York》:分析Welcome出现次数

song = '''
Welcome to New York - Taylor Swift
Walking through a crowd the village is aglow
Kaleidoscope of loud heartbeats under coats
Everybody here wanted something more
Searching for a sound we hadn't heard before
And it said
Welcome to New York
It's been waiting for you
Welcome to New York
Welcome to New York
Welcome to New York
It's been waiting for you
Welcome to New York
Welcome to New York
It's a new soundtrack
I can dance to this beat (beat)
Forevermore
The lights are so bright
But they never blind me (me)
Welcome to New York
It's been waiting for you
Welcome to New York
Welcome to New York
When we first dropped our bags on apartment floors
Took our broken hearts put them in a drawer
Everybody here was someone else before
And you can want who you want
Boys and boys and girls and girls
Welcome to New York
It's been waiting for you
Welcome to New York
Welcome to New York
Welcome to New York
It's been waiting for you
Welcome to New York
Welcome to New York
It's a new soundtrack
I can dance to this beat (beat)
Forevermore
The lights are so bright
But they never blind me (me)
Welcome to New York
It's been waiting for you
Welcome to New York
Welcome to New York
Like any great love it keeps you guessing
Like any real love it's ever-changing
Like any true love it drives you crazy
But you know you wouldn't change anything anything anything
Welcome to New York
It's been waiting for you
Welcome to New York
Welcome to New York
Welcome to New York
It's been waiting for you
Welcome to New York
Welcome to New York
It's a new soundtrack
I can dance to this beat
The lights are so bright
But they never blind me
Welcome to New York
New soundtrack
It's been waiting for you
Welcome to New York
The lights are so bright
But they never blind me
Welcome to New York
So bright
They never blind me
Welcome to New York
Welcome to New York
'''
word = 'Welcome'
print(word+'出现'+str(song.count('Welcome'))+'次')

将字符串分解成一个个的单词。

六级满分作文去掉标点符号后，分解成一个个单词，并了统计每个单词出现次数

article = '''
    "avoid the rush-hours" must be the slogan of large cities the world over. whe rever you go, especially 
at week-ends or on holidays, you'll find that the tr ains a re packed, streets crowded, buses queued, restaurant 
tables shared. moreover, the smallest unforeseen event like a power-cut, an exceptionally heavy snowfall or rainfall 
can bring about conditions of utterinconvenience and chaos.
 　　city-dwellers are obliged by their environment to adopt 
a wholly unnatural way of life. theylose touch with nature and all the simple, good things of life like sunshine and 
f resh air atapremium . tall buildings block out the sun. traffic fumes pollute the atmosphere. the flow oftraffic 
goes on unceasingly and the noise never stops.
 　　the funny thing about it all in a large modern city is that you pay 
dearly for the "privilege" ofliving. the demand for accommodation is so great that it is of ten impossible for 
ordinarypeople to buy a house/flat of their own. furthermore, the cost of living is very high. just abouteve rything 
you buy is likely to be more expensive than it would be in the country.
 　　in addition, city-dwellers live under 
constant threat. the crime rate in most cities is very high. houses are often burgled. cities breed crime and 
violence and are full of places you would beafr aid to visit at night. if you think about it, they are not really fit 
to live in at all. can anyonereally doubt that the country is what man was born for and where he truly belongs? '''
replace = ['"', '.', '?', ',', '(', ')']
for i in replace:
    article = article.replace(i, ' ')
artarray = article.split()
print(artarray)
for i in artarray:
    print(i+'出现'+str(article.count(i))+'次')

 

2.组合数据类型练习

分别定义字符串，列表，元组，字典，集合，并进行遍历。

字符串：

string = 'string'
for i in string:
    print(i)

列表：

ls = list(range(5))
ls2 = list('turtle')
ls3 = ['h', 'e', 'l', 'l', 'o']
for i in ls:
    print(i)
for i in ls2:
    print(i)
for i in ls3:
    print(i)

元组：

ls1 = list(range(5))
ls2 = list('turtle')
tuple1 = tuple(ls1)
tuple2 = tuple(ls2)
tuple3 = ('h', 'e', 'l', 'l', 'o')
for i in tuple1:
    print(i)
for i in tuple2:
    print(i)
for i in tuple3:
    print(i)

字典：

dict = dict(zip('turtle', '123456'))
for i in dict:
    print(i)
for i in dict.keys():
    print(i)
for i in dict.values():
    print(i)
for i in dict.items():
    print(i)

集合：

ls = list('turtle')
set = set(ls)
for i in set:
    print(i)

 

总结列表，元组，字典，集合的联系与区别。

联系：

　　元组、字典、集合都可以通过预先定义列表来进行创建；

　　并且元组中可以含有列表、列表中也可以包含元组；

　　元组中的列表的元素可以修改；

　　集合中的元素就是字典中的键值；

　　列表，元组，字典，集合之间可以相互转化。

 

区别：

　　元组和列表是有序列的，字典和集合是无序列的；

　　元组中除了列表元素里的元素可修改以外，其他不可以修改；

　　字典中的键不可以修改，值可以修改；

　　元组不能使用列表的方法增加自身的元素，集合可以使用add()方法添加元素；

　　元组和列表的元素可以重复，字典和集合的元素不能重复。