argparse模块

argparse模块是python用于命令行参数和选项解析的标准模块，用于替代已经过时的optparse模块。

使用步骤：

 import   argparse

parser = argparse.ArgumentParser()

parser.add_argument()

parser.parse_args()

导入该模块，然后创建一个解析对象，向该对象中添加你要关注的命令行参数和选项，每个add_argment()方法对应一个你要关注的参数或选项，最后调用parse_args()方法进行解析；解析成功后即可使用。

三、方法ArgumentParser()

三、方法ArgumentParser(prog=None, usage=None,description=None, epilog=None, parents=[],formatter_class=argparse.HelpFormatter, prefix_chars='-',fromfile_prefix_chars=None, argument_default=None,conflict_handler='error', add_help=True)

这些参数都有默认值，当调用parser.print_help()或者运行程序时由于参数不正确(此时python解释器其实也是调用了pring_help()方法)时，会打印这些描述信息，一般只需要传递description参数，如上。

四、方法add_argument(name or flags...[, action][, nargs][, const][, default][, type][, choices][, required][, help][, metavar][, dest])

其中：

name or flags：命令行参数名或者选项，如上面的address或者-p,--port.其中命令行参数如果没给定，且没有设置defualt，则出错。但是如果是选项的话，则设置为None

nargs：命令行参数的个数，一般使用通配符表示，其中，'?'表示只用一个，'*'表示0到多个，'+'表示至少一个

default：默认值

type：参数的类型，默认是字符串string类型，还有float、int等类型

help：和ArgumentParser方法中的参数作用相似，出现的场合也一致

import argparse

 

def parse_args():

    description = usage: %prog [options] poetry-file

 

This is the Slow Poetry Server, blocking edition.

Run it like this:

 

  python slowpoetry.py <path-to-poetry-file>

 

If you are in the base directory of the twisted-intro package,

you could run it like this:

 

  python blocking-server/slowpoetry.py poetry/ecstasy.txt

 

to serve up John Donne's Ecstasy, which I know you want to do.

 

 

    parser = argparse.ArgumentParser(description = description)

     

    help = The addresses to connect.

    parser.add_argument('addresses',nargs = '*',help = help)

 

    help = The filename to operate on.Default is poetry/ecstasy.txt

    parser.add_argument('filename',help=help)

 

    help = The port to listen on. Default to a random available port.

    parser.add_argument('-p',--port', type=int, help=help)

 

    help = The interface to listen on. Default is localhost.

    parser.add_argument('--iface', help=help, default='localhost')

 

    help = The number of seconds between sending bytes.

    parser.add_argument('--delay', type=float, help=help, default=.7)

 

    help = The number of bytes to send at a time.

    parser.add_argument('--bytes', type=int, help=help, default=10)

 

    args = parser.parse_args();

    return args

 

if __name__ == '__main__':

    args = parse_args()

     

    for address in args.addresses:

        print 'The address is : %s .' % address

     

    print 'The filename is : %s .' % args.filename

    print 'The port is : %d.' % args.port

    print 'The interface is : %s.' % args.iface

    print 'The number of seconds between sending bytes : %f'% args.delay

    print 'The number of bytes to send at a time : %d.' % args.bytes</path-to-poetry-file>







运行该脚本：python test.py --port 10000 --delay 1.2 127.0.0.1 172.16.55.67 poetry/ecstasy.txt

 

输出为：

The address is : 127.0.0.1 .
The address is : 172.16.55.67 .
The filename is : poetry/ecstasy.txt .
The port is : 10000.
The interface is : localhost.
The number of seconds between sending bytes : 1.200000
The number of bytes to send at a time : 10.