字符串操作练习：星座、凯撒密码、99乘法表、词频统计预处理

1、凯撒密码

plaincode=input('明文：')
s=ord('a')
print('密文:',end='')
for i in plaincode:
    if s<= ord(i)<=ord('z'):
        print(chr(s+(ord(i)-s+3)%26),end='')
    else:
        print(i,end='')
    

2、星座符号

for i in range(12):
    print(chr(9800+i),end='/')

 4、输入姓名，格式输出：占4位、居中、不足4字的以空格填充。

name=input('输入姓名：')
print('你的名字：{0:' '^4}'.format(name))

5、格式化输出：中华人民共和国国内生产总值(GDP)689,136.89亿元(2015年)（千分位、2位小数，浮点数）

 year = input("请输入年份：")
 gdp = float(input("请输入{}年的GDP：".format(year)))
 print("中华人民共和国国内生产总值(GDP){0:,.2f}亿元({1}年)".format(gdp,year))

6、实例：打出99乘法表

 for i in range(1,10):
     for j in range(1,10):
         print("{}x{}={}".format(i,j,i*j),end=' ')
         if i==j:
             print("
")
             break

 

7、实例: 下载一首英文的歌词或文章，统计单词出现的次数，将所有,.？！替换为空格，将所有大写转换为小写。

geci = '''An empty street An empty house !
A hole inside heart? 
I'm all, alone and the rooms.
Are getting smaller 
I wonder how !I wonder why !
I wonder where they are 
geci=The !days we had .
The songs we sang together .
And oh! my love !
I'm holding on forever? ?
Reaching? for a love! 
That seems ?so far 
So I? say a litter prayer 
No my dream will take me there 
Where the skies are blue to see you 
once again my love 
Overseas from coast to coast 
Find, a place I love the most! 
Where the fields are green 
To see you once again  '''


print(geci.count('love'))
for i in geci:
    geci=geci.replace(',',' ')
    geci=geci.replace('.',' ')
    geci=geci.replace('!',' ')
    geci=geci.replace('?',' ')
print(geci)
print (geci.lower())

 8、用webbrowser，uweb.open_new_tab('url')打开校园新闻列表

import webbrowser as web
for i in range(2,5):
    web.open_new_tab('http://news.gzcc.cn/html/xiaoyuanxinwen/'+str(i)+'.html')