python 基础之第二天

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

 sum = 0
 counter = 0

 while counter < 101:
 　　sum += counter
 　　counter += 1
 print sum

 [root@master script]# cat game.py
 #!/usr/bin/python
 # coding: utf-8
 import random
 ch_list = ["剪刀","石头","布"]
 prompt = """
 (0) 剪刀
 (1) 石头
 (2) 布
 请选择(0/1/2):
 """
 win_list = [["石头","剪刀"],["布","石头"],['剪刀',"布"]]
 computer = random.choice(ch_list)
 ind = int(raw_input(prompt))
 player = ch_list[ind]

 print 'Your_choice:%s,computer_choice:%s' % (player,computer)

 if [player,computer] in win_list:
     print '\033[31;1mplayer win !!!!\033[0m'
 elif player == computer:
     print '\033[32;1m平局\033[0m'

 else:
     print '\033[33;1mcomputer win!!!\033[0m'

###############range用法################

 >>> range(10)
 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
 >>> range(1,10,2)
 [1, 3, 5, 7, 9]
 >>> range(2,10,2)
 [2, 4, 6, 8]
 >>> range(10,1,-1)
 [10, 9, 8, 7, 6, 5, 4, 3, 2]

##################len用法###############

 [fush@xm35 ~ 11:11:47]$ vim alist.py
 #!/usr/bin/python
 # coding: utf-8

 alist = ['bob','jerry','hali','cherry']

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

 [fush@xm35 ~ 11:12:11]$ python alist.py
 0: bob
 1: jerry
 2: hali
 3: cherry

###############斐波那契数列##############

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

alist = [0,1]

for i in range(8):
    sum = alist[-1] + alist[-2]
    alist.append(sum)
for n in alist:
    print n,

[root@master script]# python fbnq.py
0 1 1 2 3 5 8 13 21 34

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

alist = [0,1]
num = int(raw_input('Please a number: '))
for i in range(num):
    sum = alist[-1] + alist[-2]
    alist.append(sum)
for n in alist:
    print n,

[root@master script]# python fbnq.py
Please a number: 11
0 1 1 2 3 5 8 13 21 34 55 89 144
[root@master script]# python fbnq.py
Please a number: 9
0 1 1 2 3 5 8 13 21 34 55

###############os.system 返回码###############

os.system()操作的结果是一个等价于echo $? 的一个值，成功为0，不成功非0值

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

 import os

 result = os.system('cat /etc/passwd &> /dev/null')
 print result

 [root@master script]# python system.py
 0

ping 主机连通性例子：

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

 import os

 for i in range(1,255):
     ip = '192.168.244.%s' % i
     result = os.system('ping -c2 %s &> /dev/null' % ip)
     if result:
         print '%s: down' % ip
     else:
         print '%s: up' % ip

 检测：
 [root@master script]# python ping.py
 192.168.244.1: down
 192.168.244.2: up
 192.168.244.3: down
 192.168.244.4: down
 192.168.244.5: down

多线程：

##################解析列表##############

 >>> ['hello' for i in range(3)]
 ['hello', 'hello', 'hello']
 >>> [10 for i in range(3)]
 [10, 10, 10]
 >>> [i for i in range(10)]
 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
 >>> [i**2 for i in range(10)]
 [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]
 >>> [i**2 for i in range(10) if i%2]
 [1, 9, 25, 49, 81]

#############文件对象##############

1.文件读取

例子：

 >>> f = open('/etc/hosts')
 >>> data = f.read()
 >>> print data,
 127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
 ::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
 192.168.244.200 master
 192.168.244.201 slave1
 192.168.244.202 slave2
 >>> f.close()

2.文件写入

 >>> f= open('hi.txt','w')
 >>> f.write('hello\n')
 >>> f.close()
 >>> f= open('hi.txt','a')
 >>> f.write('fush\n')
 >>> f.flush()
注释：‘w’表示以只写方式，不能读取，再次写入内容会覆盖前面的内容，‘a’ 追加内容
>>> f.writelines(['1st line.\n','2th line.\n'])

[root@master script]# cat /root/hi.txt
111
1st line.
2th line.

###########cp例子###########

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

 f = open('/etc/passwd')
 k = open('/root/passwd','a')
 while True:
     data = f.read(4096)
     if not data:
         break
     k.write(data)

 f.close()
 k.close()

 检测：
 [root@master script]# python cp.py
 [root@master script]# cat /root/passwd
 root:x:0:0:root:/root:/bin/bash
 bin:x:1:1:bin:/bin:/sbin/nologin
 daemon:x:2:2:daemon:/sbin:/sbin/nologin
 adm:x:3:4:adm:/var/adm:/sbin/nologin
 lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
 sync:x:5:0:sync:/sbin:/bin/sync
 shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
 halt:x:7:0:halt:/sbin:/sbin/halt
 mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
 uucp:x:10:14:uucp:/var/spool/uucp:/sbin/nologin
 operator:x:11:0:operator:/root:/sbin/nologin
 games:x:12:100:games:/usr/games:/sbin/nologin
 gopher:x:13:30:gopher:/var/gopher:/sbin/nologin
 ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin
 nobody:x:99:99:Nobody:/:/sbin/nologin
 vcsa:x:69:69:virtual console memory owner:/dev:/sbin/nologin
 saslauth:x:499:76:Saslauthd user:/var/empty/saslauth:/sbin/nologin
 postfix:x:89:89::/var/spool/postfix:/sbin/nologin
 sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin

 改进版：函数方式

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

 def cp(sfname,dfname):
     f = open(sfname)
     k = open(dfname,'w')
     while True:
          data = f.read(4096)
          if not data:
              break
          k.write(data)

     f.close()
     k.close()
 sname = raw_input('source_name: ')
 dname = raw_input('destination_name: ')
 cp(sname,dname)

 检测：
 [root@master script]# python cp.py
 source_name: /etc/passwd
 destination_name: /usr/local/src/passwd
 [root@master script]# cat /usr/local/src/passwd
 root:x:0:0:root:/root:/bin/bash
 bin:x:1:1:bin:/bin:/sbin/nologin
 daemon:x:2:2:daemon:/sbin:/sbin/nologin
 adm:x:3:4:adm:/var/adm:/sbin/nologin
 lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
 sync:x:5:0:sync:/sbin:/bin/sync
 shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
 halt:x:7:0:halt:/sbin:/sbin/halt
 mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
 uucp:x:10:14:uucp:/var/spool/uucp:/sbin/nologin
 operator:x:11:0:operator:/root:/sbin/nologin
 games:x:12:100:games:/usr/games:/sbin/nologin
 gopher:x:13:30:gopher:/var/gopher:/sbin/nologin
 ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin
 nobody:x:99:99:Nobody:/:/sbin/nologin
 vcsa:x:69:69:virtual console memory owner:/dev:/sbin/nologin
 saslauth:x:499:76:Saslauthd user:/var/empty/saslauth:/sbin/nologin
 postfix:x:89:89::/var/spool/postfix:/sbin/nologin
 sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin

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

 import sys
 def cp(sfname,dfname):
     f = open(sfname)
     k = open(dfname,'w')
     while True:
          data = f.read(4096)
          if not data:
              break
          k.write(data)

     f.close()
     k.close()
 cp(sys.argv[1],sys.argv[2])

 检测：
 [root@master script]# python cp.py /etc/hosts /home/zhuji
 [root@master script]# cat !$
 cat /home/zhuji
 127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
 ::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
 192.168.244.200 master
 192.168.244.201 slave1
 192.168.244.202 slave2

##############函数初识##################

[root@master ~]# vim func01.py
#!/usr/bin/python
# coding:utf-8

def pstar():
    print '*' * 20
    print '#' * 20

a= pstar()
print a

[root@master ~]# python func01.py
********************
####################
None             
备注：当函数没有返回值，返回None

形参例子：
 1 [root@master ~]# vim func01.py
 #!/usr/bin/python
 # coding:utf-8

 def pstar(num):
     return '*' * num

 n = int(raw_input('number: '))
     print pstar(n)

 [root@master ~]# python func01.py
 number: 15
 ***************

默认参数例子：

[root@master ~]# vim func01.py
#!/usr/bin/python
# coding:utf-8

def pstar(num=20):
     return '*' * num

n = int(raw_input('number: '))
print pstar()
print pstar(n)

[root@master ~]# python func01.py
number: 15
********************
***************

备注：调用函数不带参数时，用默认参数20；有带参数时，不用默认，会覆盖默认的参数

##############函数的位置参数#############

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

 import sys

 print sys.argv

 检测：
 [root@master script]# ./position.py
 ['./position.py']
 [root@master script]# ./position.py hello
 ['./position.py', 'hello']
 [root@master script]# ./position.py hello fush
 ['./position.py', 'hello', 'fush']
备注：sys.argv 是一个list

###############模块相关################

 >>> import string
 >>> string.upper('abc')
 'ABC'
 >>> string.__file__
 '/usr/lib64/python2.6/string.pyc'     ###string模块文件位置

 查看模块文件：
 [root@master script]# vim /usr/lib64/python2.6/string.py
 """A collection of string operations (most are no longer used).

 Warning: most of the code you see here isn't normally used nowadays.
 Beginning with Python 1.6, many of these functions are implemented as
 """A collection of string operations (most are no longer used).

 导入模块：
 >>> from random import choice    ##只导入random的choice
 >>> choice('adfe')
 'a'
 >>> choice('adfe')
 'a'
 >>> choice('adfe')
 'd'
 >>> choice('adfe')
 'd'
 >>> choice('adfe')
 'e'
 >>> choice('adfe')
 'f'
 >>> random.choice('fush')          ###前面没有导入random，会报错
 Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
 NameError: name 'random' is not defined
 >>> import random as rdm     ##把random模块起了个别名rdm
 >>> rdm.choice('fush')
 's'
 >>> rdm.choice('fush')
 's'
 >>> rdm.choice('fush')
 'f'