python 基础之第四天

例子1：

打印列表每个元素对应的索引

[root@master script]# vim suoyin.py
#!/usr/bin/python
# coding:utf-8

alist = ['fu','shan','hua','hive']

for i in range(len(alist)):
    print '%s:%s' % (i,alist[i])

检验：
[root@master script]# python suoyin.py
0:fu
1:shan
2:hua
3:hive
另外一种方式：

[root@master script]# vim suoyin.py
#!/usr/bin/python
# coding:utf-8

alist = ['fu','shan','hua','hive']

#for i in range(len(alist)):
#    print '%s:%s' % (i,alist[i])


for i in enumerate(alist):
    print '%s:%s' %(i[0],i[1])

检验：
[root@master script]# python suoyin.py
(0, 'fu')
(1, 'shan')
(2, 'hua')
(3, 'hive')

[root@master script]# vim suoyin.py
#!/usr/bin/python
# coding:utf-8

alist = ['fu','shan','hua','hive']

#for i in range(len(alist)):
#　　print '%s:%s' % (i,alist[i])

for i in enumerate(alist):
　　print '%s:%s' % (i[0],i[1])

检验：

[root@master script]# python suoyin.py
0:fu
1:shan
2:hua
3:hive

还可以：

[root@master script]# vim suoyin.py   
#!/usr/bin/python
# coding:utf-8

alist = ['fu','shan','hua','hive']

for m,n in enumerate(alist):
    print '%s:%s' % (m,n)

检验：
[root@master script]# python suoyin.py
0:fu
1:shan
2:hua
3:hive

#######列表一些简单用法############

In [10]: alist = [23,10,45,33]

In [11]: reversed(alist)
Out[11]: <listreverseiterator at 0x7f44bd7c3910>

In [12]: list(reversed(alist))
Out[12]: [33, 45, 10, 23]

In [15]: sorted(alist)           #从小到大，升序
Out[15]: [10, 23, 33, 45]

  In [16]: list(reversed(sorted(alist)))      #降序排列
  Out[16]: [45, 33, 23, 10]

  或者：

  In [18]: sorted(alist)[::-1]

  Out[18]: [45, 33, 23, 10]

##########字符串格式化############

In [19]: '%10s%s' % ('name','fush')     ##'%10s' 右对齐，占是个字符，不够的用空格补上；默认右对齐
Out[19]: '      namefush'

In [20]: '%10s %s' % ('name','fush')
Out[20]: '      name fush'

In [21]: '%-10s %s' % ('name','fush')         ##'%-10s' 左对齐，占是个字符，不够的用空格补上

  Out[21]: 'name      fush'

还有一种不常用的用法：

In [22]: '%*s %*s' % (-20,'name',-8,'fush')    ##在s前面用*号，在后面用数字代替
Out[22]: 'name                 fush    '

格式化案例：

[root@master script]# vim  huamian.py   
#!/usr/bin/python
# coding:utf-8


def get_content():
    contents = []
    while True:
        data = raw_input('<Enter to quit>: ')
        contents.append(data)
        if not data:
            break
    return contents

if __name__ == '__main__':
    width = 48
    lines = get_content()
    lines.pop()
    print '+%s+' % ('#' * width)
    for line in lines:
        if not len(line)%2:
            sp_width = (width -len(line)) / 2
            print '+%s%s%s+' % (' ' * sp_width,line,' ' * sp_width)
        else:
            sp_width = (width -len(line)) / 2
            print '+%s%s%s +' % (' ' * sp_width,line,' ' * sp_width)
    print '+%s+' % ('#' * width)

改进版：

#!/usr/bin/python
# coding:utf-8


def get_content():
    contents = []
    while True:
        data = raw_input('<Enter to quit>: ')
        if not data:
            break
        contents.append(data)
    return contents

if __name__ == '__main__':
    width = 48
    lines = get_content()
    print '+%s+' % ('#' * width)
    for line in lines:
        sp_width , extra = divmod((width -len(line)),2)
        print '+%s%s%s+' % (' ' * sp_width,line,' ' * (sp_width + extra))
    print '+%s+' % ('#' * width)
备注：num1,num2 = divmod(10,2)
num1 = 10/2 的商
num2 = 10/2 的余数
奇数/2 的余数（num2=1）
偶数/2 的余数（num2=0） 

验证效果：

[root@master script]# python  huamian.py
<Enter to quit>: hello
<Enter to quit>: world!
<Enter to quit>: 
+################################################+
+                     hello                      +
+                     world!                     +
+################################################+

 ##########另外一种格式化#############

>>> import string
>>> data = 'hello $name,I will see you $day'
>>> t = string.Template(data)
>>> t.substitute(name='tony',day='afternoon')
'hello tony,I will see you afternoon'
>>> t.substitute(name='herry',day='afternoon')
'hello herry,I will see you afternoon'

###########添加用户和密码以及发邮件通知案例#############

首先编写一个获取随机密码的文件：

#!/usr/bin/python
# coding:utf-8

import string
import random
import sys


def get_pass():
    pwd = ''
    for i in range(8):
         char = random.choice(string.lowercase + string.uppercase + string.digits)
         pwd += char
    return pwd
if __name__ == '__main__':
    print get_pass()

正式文件代码：

[root@master script]# cat adduser.py 
#!/usr/bin/python
# coding:utf-8

import sys
import os
import ranpass
import string

contents = """username: ${username}
password: ${password}

"""

t = string.Template(contents)

def adduser(user,pwd,email):
    data = t.substitute(username =user,password = pwd)
    os.system('useradd %s' % username)
    os.system('echo %s |passwd --stdin %s' % (pwd,username))
    os.system('echo -e "%s" |mail -s "user info" %s' % (data,email))


if __name__ == '__main__':
    username = sys.argv[1]
    pwd = ranpass.get_pass()
    adduser(username,pwd,'root@localhost')

 检验：

[root@master script]# chmod +x adduser.py
[root@master script]# ./adduser.py tiantian  
useradd: user 'tiantian' already exists
Changing password for user tiantian.
passwd: all authentication tokens updated successfully.
[root@master script]# cat /var/spool/mail/root |more

From root@master.localdomain  Fri Aug  4 18:32:36 2017
Return-Path: <root@master.localdomain>
X-Original-To: root@localhost
Delivered-To: root@localhost.localdomain
Received: by master.localdomain (Postfix, from userid 0)
        id 844AE22CD3; Fri,  4 Aug 2017 18:32:36 +0800 (CST)
Date: Fri, 04 Aug 2017 18:32:36 +0800
To: root@localhost.localdomain
Subject: user info
User-Agent: Heirloom mailx 12.4 7/29/08
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Message-Id: <20170804103236.844AE22CD3@master.localdomain>
From: root@master.localdomain (root)

username: tiantian
password: GJh4t646



[root@master script]# mail
Heirloom Mail version 12.4 7/29/08.  Type ? for help.
"/var/spool/mail/root": 1 message 1 new
>N  1 root                  Fri Aug  4 18:32  21/635   "user info"
& 1
Message  1:
From root@master.localdomain  Fri Aug  4 18:32:36 2017
Return-Path: <root@master.localdomain>
X-Original-To: root@localhost
Delivered-To: root@localhost.localdomain
Date: Fri, 04 Aug 2017 18:32:36 +0800
To: root@localhost.localdomain
Subject: user info
User-Agent: Heirloom mailx 12.4 7/29/08
Content-Type: text/plain; charset=us-ascii
From: root@master.localdomain (root)
Status: R

username: tiantian
password: GJh4t646



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