Python命令行参数解析模块optparse使用实例

示例

from optparse import OptionParser

[...]

def main():

    usage = "usage: %prog [options] arg"

    parser = OptionParser(usage)

    parser.add_option("-f", "--file", dest="filename",

                      help="read data from FILENAME")

    parser.add_option("-v", "--verbose",

                      action="store_true", dest="verbose")

    parser.add_option("-q", "--quiet",

                      action="store_false", dest="verbose")

    [...]

    (options, args) = parser.parse_args()

    if len(args) != 1:

        parser.error("incorrect number of arguments")

    if options.verbose:

        print "reading %s..." % options.filename

    [...]
if __name__ == "__main__":

    main()

增加选项(add_option())

OptionParser.add_option(option)

OptionParser.add_option(*opt_str, attr=value, ...)

定义短选项

parser.add_option(“-f”, attr=value, …)

定义长选项

parser.add_option(“?foo”, attr=value, …)

如果定义

​parser.add_option("-f", "--file", action="store", type="string", dest="filename")

命令行格式可以有以下形式

-ffoo

-f foo

--file=foo

--file foo

解析后结果

options.filename = “foo”

解析(parse_args())

(options, args) = parser.parse_args()

options 解析后的参数,以字典形式保存
args 不能解析的参数,以列表形式保存

行为(action)

●store 默认行为,保存值到dest
●“store_const” 保存常量
●“append” append this option's argument to a list
●“count” increment a counter by one
●“callback” call a specified function

设置默认值(default)

parser.add_option("-v", action="store_true", dest="verbose", default=True)

parser.set_defaults(verbose=True)

生成帮助提示(help)

提供help选项即可,可以用parser.print_help()打印出来

parser.add_option(“-f”, “?file”, dest=”filename”,help=”write report to FILE”, metavar=”FILE”)

设置boolean值

支持store_true和store_false两个行为

parser.add_option("-v", action="store_true", dest="verbose")

parser.add_option("-q", action="store_false", dest="verbose")

如果遇到-v,verbose=True;如果遇到-q,verbose=False

错误处理

(options, args) = parser.parse_args()

[...]

if options.a and options.b:

    parser.error("options -a and -b are mutually exclusive")

选项组(Grouping Options)

格式如下

class optparse.OptionGroup(parser, title, description=None)

group = OptionGroup(parser, "Dangerous Options",

                    "Caution: use these options at your own risk.  "

                    "It is believed that some of them bite.")

group.add_option("-g", action="store_true", help="Group option.")

parser.add_option_group(group)

提示结果如下

Usage: <yourscript> [options] arg1 arg2
Options:

  -h, --help            show this help message and exit

  -v, --verbose         make lots of noise [default]

  -q, --quiet           be vewwy quiet (I'm hunting wabbits)

  -f FILE, --filename=FILE

                        write output to FILE

  -m MODE, --mode=MODE  interaction mode: novice, intermediate, or

                        expert [default: intermediate]
  Dangerous Options:

    Caution: use these options at your own risk.  It is believed that some

    of them bite.
    -g                  Group option.