字符串练习：
http://news.gzcc.cn/html/2017/xiaoyuanxinwen_1027/8443.html
取得校园新闻的编号
str = 'http://news.gzcc.cn/html/2017/xiaoyuanxinwen_1027/8443.html' print(str[-14:-5]) https://docs.python.org/3/library/turtle.html
产生python文档的网址
addr1 = 'https://docs.python.org/3/library/'
addr2 = ['turtle', 'index', 'sys']
addr3 = '.html'
for i in addr2:
print(addr1 + i + addr3)
产生校园新闻的一系列新闻页网址
for i in range(2, 231):
address = 'http://news.gzcc.cn/html/xiaoyuanxinwen/{}.html'.format(i)
print(address)
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:])
用函数统计一歌词中单词出现的次数
song = '''I never knew
When the clock stopped and I'm looking at you
I never thought I'll miss someone like you
Someone I thought that I knew
I never knew
I should have known something wouldn't be true
Baby you know that I'm so into you
More than I know I should do
So why why why
Why should we waited
And I I I
I should be waiting
Waiting for someone new
Even though that it wasn't you
But I know that it's
Wonderful
Incredible
Baby irrational
I never knew it was obsessional
And I never knew it was with you oooh
Baby if it's just
Wonderful
Incredible
Baby irrational
I never knew it was so sad
Just so sad
I'm so sorry
Even now I just cannot feel you feel me
Hmmm
So why why why
Why should we waited
And I I I
I should be waiting
Waiting for someone new
Even though that it wasn't you
But I know that it's
Wonderful
Incredible
Baby irrational
I never knew it was obsessional
And I never knew it was with you oooh
Baby if it's just
Wonderful
Incredible
Baby irrational
I never knew it was so sad
Just so sad
I'm so sorry
Even now I just cannot feel you fall
I don't even know now
I'm sure you'll wait for me
Even now I just cannot deny
I just hold on so tight
Until you and I never could breathe
Oh
Wonderful
Incredible
Baby irrational
I never knew it was obsessional
And I never knew it was with you until you tell me to
Baby if it's just
Wonderful
Incredible
Baby irrational
I never knew it was so sad
Just so sad
I'm so sorry
Even now I just cannot feel you feel me
'''
print(song.count('Wonderful'))
将字符串分解成一个个的单词。
a = 'I love study Python!' print(a.split())