Python语句

>>> range(10)  #表示一段范围,起始不写表示从0开始,结束不包含

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

>>> range(1, 11)

[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

>>> range(5, 11)

[5, 6, 7, 8, 9, 10]

>>> range(1, 11, 2) #起始写了表示从起始开始,后面的11不包含,2表示步长值

[1, 3, 5, 7, 9]

>>> range(2, 11, 2)

[2, 4, 6, 8, 10]

>>> range(10, 0, -1)

[10, 9, 8, 7, 6, 5, 4, 3, 2, 1]

列表解析

>>> [10]

[10]

>>> [20 + 20]

[40]

>>> [10 + 10 for i in range(5)]

[20, 20, 20, 20, 20]

>>> [10 + i for i in range(5)]

[10, 11, 12, 13, 14]

>>> [10 + i for i in range(1, 11)]

[11, 12, 13, 14, 15, 16, 17, 18, 19, 20]

>>> [10 + i for i in range(1, 11) if i % 2 == 1]#把列表中的基数解析出来

[11, 13, 15, 17, 19]

>>> [10 + i for i in range(1, 11) if i % 2 == 0]#把列表中的偶数解析出来

[12, 14, 16, 18, 20]

>>> ['192.168.1.%s' % i for i in range(1, 5)]

['192.168.1.1', '192.168.1.2', '192.168.1.3', '192.168.1.4'] #ip地址表示方法

文件读取方法:

>>> f = open('/etc/passwd')

>>> data = f.read()

>>> f.close()

>>> data

>>> print data

>>> f = open('/etc/passwd') #常用for循环语句读取数据

>>> for line in f:

...   print line,

>>> f = open('/tmp/hello.txt', 'w')

>>> 

>>> f.write('hello the world')

>>> f.flush()

>>> f.write("\n")

>>> f.flush()

>>> f.write('33333333\n')

>>> f.flush()

>>> f.writelines(['aaa\n', '3rd line\n'])

>>> f.flush()

f1 = open('/bin/ls')

f2 = open('/root/ls', 'w')

data = f1.read()

f2.write(data)

f1.close()

f2.close()

md5sum /bin/ls /root/ls #产看两个文件的属性是否相同,用md5sum查看 

def gen_fibs(l):  #定义函数用def gen_fibs()

    fibs = [0, 1]

    for i in range(l-2):

        fibs.append(fibs[-1] + fibs[-2])

    return fibs

a = int(raw_input('length: '))

print gen_fibs(a)  #调用函数

print gen_fibs(20)

try:

    num = int(raw_input("number: "))

    result = 100 / num

except ValueError:

    print 'You must input a number'

except ZeroDivisionError:

    print '0 is not allowed'

except (KeyboardInterrupt, EOFError):

    print '\nBye-bye'

else:

    print result #出现异常才会打印

finally:

    print 'Done' #不管出不出现异常最终都会输出Done

def set_age(name, age):

    if not 0 < age < 150:

        raise ValueError, 'age out of range' #相当于主动触发异常,用关键字raise,后面跟要引发的异常的名称

    print '%s is %s years old' % (name, age)

def set_age2(name,age):

    assert 0 < age < 150, 'age out of range' #断言异常的肯定，用关键字assert

    print '%s is %s years old' % (name, age)

if __name__ == '__main__':

    set_age('hanjie', 22)

    set_age2('hanjie', 220)

>>> with open('/etc/passwd') as f:

...     f.readline()

... 

'root:x:0:0:root:/root:/bin/bash\n'

正则表达式：%s/\(..\)\(..\)\(..\)\(..\)\(..\)\(..\)$/\1:\2:\3:\4:\5:\6/

192.168.1.1      00000ac15658   #没有转换之前

192.168.1.2      5253000a1234

192.168.1.3      5356afc35695

192.168.1.1      00:00:0a:c1:56:58 #转化之后

192.168.1.2      52:53:00:0a:12:34

192.168.1.3      53:56:af:c3:56:95

查看用户日志：

import re

def count_patt(fname, patt):

    result = {}

    cpatt = re.compile(patt)

    fobj = open(fname)

    for line in fobj:

        m = cpatt.search(line)

        if m:

            key = m.group()

            if key not in result:

                result[key] = 1

            else:

                result[key] += 1

        fobj.close()

        return result

if __name__ == '__main__':

    fname = 'access_log'

    ip_patt = '^(\d+\.){3}\d+'

    br_patt = 'Firefox|MISE|Chrome'

    print count_patt(fname, ip_patt)

    print count_patt(fname, br_patt)

Python中使用的快捷方式'tab'键

vim /usr/local/bin/tab.py

from rlcompleter import readline

readline.parse_and_bind('tab: complete')

vim ~/.bashrc

export PYTHONSTARTUP=/usr/local/bin/tab.py

source .bashrc

用Python编程创建用户：

import sys

import subprocess

import randpass

def adduser(username, fname):

    password = randpass.gen_pass()

    info = """user information:

    username: %s

    password: %s"""

    subprocess.call('useradd %s' % username, shell=True)

    subprocess.call('echo %s | passwd --stdin %s' % (password, username), shell=True)

    with open(fname, 'a') as fobj:

        fobj.write(info % (username, password))

if __name__ == '__main__':

    adduser(sys.argv[1], '/tmp/user.txt')

Python编程在以网段内有多少个主机是开着的：如下

import subprocess

import threading

def ping(host):

    result = subprocess.call('ping -c2 %s &> /dev/null' % host, shell=True)

    if result == 0:

        print '%s: up' % host

    else:

        print '%s: down' % host

if __name__ == '__main__':

    ips = ['176.130.8.%s' % i for i in range(1, 255)]

    for ip in ips:

        t = threading.Thread(target=ping, args=[ip]) #调用多线成模块

        t.start()

多线程实现ssh并发访问：       

import threading

import getpass

import paramiko

import sys

import os

def remote_comm(host, pwd, command):

    ssh = paramiko.SSHClient()

    ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())

    ssh.connect(host, username= 'root', password= pwd)

    stdin, stdout, stderr = ssh.exec_command(command)

    out = stdout.read()

    error = stderr.read()

    if out:

        print "[out] %s: \n%s" %(host, out),

    if error:

        print "[error] %s: \n%s" %(host, error),

        ssh.close()

if __name__ == '__main__':

    if len(sys.argv) != 3:

        print "Usage: %s ipfile 'command'" % sys.argv[0]

        sys.exit(1)

    ipfile = sys.argv[1]

    command = sys.argv[2]

    if not os.path.isfile(ipfile):

        print "No such file:", ipfile

        sys.exit(2)

    pwd = getpass.getpass("password:")

    with open(ipfile) as fobj:

        for line in fobj:

            ip = line.strip()

            t = threading.Thread(target=remote_comm, args=(ip, pwd, command))

            t.start()

剪刀石头布当输入错误时会引发，一些错误提示

pwin = 0  #人赢的次数

cwin = 0  #电脑赢得次数

import random

all_choices = ['石头', '剪刀', '布']

win_list = [['石头', '剪刀'], ['剪刀', '布'], ['石头', '布']]

prompt = """(0)石头

(1)剪刀

(2)布

请选择(0/1/2):"""

while pwin < 2 and cwin < 2:

    computer = random.choice(all_choices)

    try:

        ind = int(raw_input(prompt))

        player = all_choices[ind]

    except (ValueError, IndexError):

        print 'Inavlid input. Try again'

        continue

    except (KeyboardInterrupt, EOFError):

        print '\nBye-bye'

        break

    print "Your choice: %s, Computer's choice: %s" %(player, computer)

    if player == computer:

        print '\033[32;1m平局\033[0m'

    elif [player,computer] in win_list:

        pwin += 1

        print '\033[31;1m你赢了\033[0m'

    else:

        cwin += 1

        print '\033[31;1m你输了\033[0m'