Python语句

2020-01-10 11:05:31 浏览数 (1)

>>> 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('33333333n')

>>> f.flush()

>>> f.writelines(['aaan', '3rd linen'])

>>> f.flush()

f1 = open('/bin/ls')

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

data = f1.read()

f2.write(data)

f1.close()

f2.close()

代码语言:javascript复制
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/bashn'

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:

代码语言:javascript复制
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 '33[32;1m平局33[0m'
    elif [player,computer] in win_list:
        pwin  = 1
        print '33[31;1m你赢了33[0m'
    else:
        cwin  = 1
        print '33[31;1m你输了33[0m'

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