python argparse子產品的簡單使用

argparse的一個使用例子：

#! /usr/bin/env python
# coding=utf8
import socket
import argparse

def setArgparse():
    parser = argparse.ArgumentParser(description="socket test")#添加子產品描述
    parser.add_argument('--host', action="store", dest="host", required=True)
    parser.add_argument('--port', action='store', dest='port', type=int, required=True)
    give_args = parser.parse_args()
    host = give_args.host
    port = give_args.port

    try:
        s= socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    except socket.error as e:
        print 'Error create socket %s'.format(e)

if __name__ == "__main__":
    setArgparse()
           

擴充例子:

import argparse
parse = argparse.ArgumentParser()
parse.add_argument("a", help="params means")
parse.add_argument("-C", "--gc", default="count")
parse.add_argument("--ga", help="params means ga",dest='simple_value',choices=['A', 'B', 'C', 0])
parse.add_argument("--gb", help="params means gb",action="store_const",const='value-to-store')
args = parse.parse_args()
print args.simple_value,args.gb,args.gc

### add_argument 說明
不帶'--'的參數
    調用腳本時必須輸入值
    參數輸入的順序與程式中定義的順序一緻
'-'的參數
    可不輸入    add_argument("-a")
    類似有'--'的shortname，但程式中的變量名為定義的參數名
'--'參數
    參數别名: 隻能是個字元，區分大小寫
        add_argument("-shortname","--name", help="params means")，但代碼中不能使用shortname
    dest: 參數在程式中對應的變量名稱 add_argument("a",dest='code_name')
    default: 參數預設值
    help: 參數作用解釋  add_argument("a", help="params means")
    type : 預設string  add_argument("c", type=int)
    action:
    store：預設action模式，存儲值到指定變量。
    store_const：存儲值在參數的const部分指定，多用于實作非布爾的指令行flag。
    store_true / store_false：布爾開關。 store_true.預設為False，輸入則為true。 store_flase 相反
    append：存儲值到清單，該參數可以重複使用。
    append_const：存儲值到清單，存儲值在參數的const部分指定。
    count: 統計參數簡寫輸入的個數  add_argument("-c", "--gc", action="count")
    version 輸出版本資訊然後退出。
    const:配合action="store_const|append_const"使用，預設值
    choices:輸入值的範圍 add_argument("--gb", choices=['A', 'B', 'C', 0])
    required : 預設False, 若為 True, 表示必須輸入該參數


==================================================================================
    Keyword Arguments:
        - option_strings -- A list of command-line option strings which    should be associated with this action.
        - dest -- The name of the attribute to hold the created object(s)
        - nargs -- The number of command-line arguments that should be  consumed. By default, one argument will be consumed and a single  value will be produced. 
                     Other values include:
                - N (an integer) consumes N arguments (and produces a list)
                - '?' consumes zero or one arguments
                - '*' consumes zero or more arguments (and produces a list)
                - '+' consumes one or more arguments (and produces a list)
                    Note that the difference between the default and nargs= is that with the default, a single value will be produced, while with  nargs=, a list containing a single value will be produced.
        - const -- The value to be produced if the option is specified and the  option uses an action that takes no values.
        - default -- The value to be produced if the option is not specified.
        - type -- A callable that accepts a single string argument, and returns the converted value.  
                    The standard Python types str, int,  float, and complex are useful examples of such callables.  If None,  str is used.
        - choices -- A container of values that should be allowed. 
                    If not None,  after a command-line argument has been converted to the appropriate type, an exception will be raised if it is not a member of this collection.
        - required -- True if the action must always be specified at the command line. This is only meaningful for optional command-line  arguments.
        - help -- The help string describing the argument.
        - metavar -- The name to be used for the option's argument with the  help string. If None, the 'dest' value will be used as the name.

           

import argparse

# sub-command functions
def subcmd_list(args):
   print "list"

def subcmd_create(args):
   print "create"

def subcmd_delete(args):
   print "delete"

parser = argparse.ArgumentParser()
subparsers = parser.add_subparsers(help='commands')

# A list command
list_parser = subparsers.add_parser('list', help='Listcontents')
list_parser.add_argument('dirname', action='store', help='Directory tolist')
list_parse.set_defaults(func=subcmd_list)

# A create command
create_parser = subparsers.add_parser('create', help='Create a directory')
create_parser.add_argument('dirname',action='store',help='New directoryto create')
create_parser.add_argument('--read-only',default=False, action='store_true',help='Setpermissions to prevent writing to the directory')
create_parser .set_defaults(func=subcmd_create)

# A delete command
delete_parser = subparsers.add_parser('delete',help='Remove a directory')
delete_parser.add_argument( 'dirname', action='store',help='The directory to remove')
delete_parser.add_argument('--recursive', '-r',default=False, action='store_true',help='Remove thecontents of the directory, too')
delete_parser .set_defaults(func=subcmd_delete)

args = parser.parse_args()
# call subcmd
args.fun(args)