字符串、组合数据类型练习

1.字符串练习：

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

取得校园新闻的编号

方法一：

str='http://news.gzcc.cn/html/2017/xiaoyuanxinwen_1027/8443.html'
print(str[-14:-5])

方法二：

str='http://news.gzcc.cn/html/2017/xiaoyuanxinwen_1027/8443.html'
n=str.rstrip('.html').split('_')[1]
print(n)

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

产生python文档的网址

add1='https://docs.python.org/3/library/'
add2=['turtle','index']
add3='.html'
for i in add2:
    print(add1+i+add3)

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(1, 20):
    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

将字符串分解成一个个的单词。

s='this is string example...   '
s1='wow'
print(s+s1)
print(s.lstrip('this'))
print(s.rstrip('...   '))
print(s.strip()+s1)
print(s.split())
print(s.split('i'))
print(s.count('s'))

用函数得到校园新闻编号

str='http://news.gzcc.cn/html/2017/xiaoyuanxinwen_1027/8443.html'
n=str.rstrip('.html').split('_')[1]
print(n)

用函数统计一歌词中单词出现的次数

str='''Heartbeats  Amy Diamond
I can't figure out
Is it meant to be this way
Easy words so hard to say
I can't live without
Knowing how you feel
Know if this is real
Tell me am I mistaken
Cause I don't have another heart for breakin'
Please don't let me go
I just wanna stay
Can't you feel my heartbeats
Giving me away
I just want to know
If you too feel afraid
I can feel your heartbeats
Giving you away
Giving us away
I can't understand
How it's making sense
That we put up such defense
When all you need to know
No matter what you do
I'm just as scared as you
Tell me am I mistaken
Cause I don't have another heart for breakin'
Please don't let me go
I just wanna stay
Can't you feel my heartbeats
Giving me away
I just want to know
If you too feel afraid
I can feel your heartbeats
Giving you away
Giving us away
Please don't let me go
I just wanna stay
Can't you feel my heartbeats
Giving me away
I just want to know
If you too feel afraid
I can feel your heartbeats
Giving you away
Giving us away'''
print(str.count('away'))

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：
s='turtle'
for i in s:
    print(i)
列表：
classmates=['Jenny','Lucy','Tidy','Alice',[1,2,3,]]
for i in classmates:
    print(i)
元祖：
tup=tuple(classmates)
tup[-1][1]=0
for i in tup :
    print(i)
字典：
d={'Bob':75,'Tracy':95,'Lisa':88}
for i in d:
    print(i)
集合：
s1={1,2,3,4,5,}
s2={1,3,6,9}
s=s1&s2
print(s)
for i in s:
    print(i)

总结列表，元组，字典，集合的联系与区别。

总结：列表和元祖都是有序的序列。元祖和列表非常相似，但是元祖不可修改，但是若元祖的某一个元素属性为列表，则该列表元素中的元素可以修改。字典和集合是无序的、不重复的。字典使用键-值（key-value）对存储，key是不可变对象。集合是一组key的集合，但不存储value。列表的元素集合用中括号，元祖用圆括号，字典和集合用大括号。