python中的argparse模块(参数解析)

FROM: https://docs.python.org/2/howto/argparse.html#id1 http://blog.itpub.net/26250550/viewspace-1281968/
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 说明

不带'--'的参数

调用脚本时必须输入值

参数输入的顺序与程序中定义的顺序一致

'-'的参数

可不输入 add_argument("-a")

类似有'--'的shortname，但程序中的变量名为定义的参数名

'--'参数

参数别名: 只能是1个字符，区分大小写

add_argument("-shortname","--name", help="params means")，但代码中不能使用shortname

dest: 参数在程序中对应的变量名称 add_argument("a",dest='code_name')

default: 参数默认值

help: 参数作用解释 add_argument("a", help="params means")

type : 默认string add_argument("c", type=int)

action:

store：默认action模式，存储值到指定变量。

store_const：存储值在参数的const部分指定，多用于实现非布尔的命令行flag。

store_true / store_false：布尔开关。可以2个参数对应一个变量。

append：存储值到列表，该参数可以重复使用。

append_const：存储值到列表，存储值在参数的const部分指定。

count: 统计参数简写输入的个数 add_argument("-c", "--gc", action="count")

version 输出版本信息然后退出。
const:配合action="store_const|append_const"使用，默认值

choices:输入值的范围 add_argument("--gb", choices=['A', 'B', 'C', 0])

==================================================================================

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=1 is that with the default, a single value will be produced, while with nargs=1, 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.

参考
http://blog.csdn.net/songuooo/article/details/8373086