问题
Currently I'm creating a directory reader program using Python. I'm using 'argparse' to parse the arguments from command line. I have the following code:
parser = argparse.ArgumentParser(prog = "LS.py",
usage = "%(prog)s [options] [path1 [path2 [...pathN]]]\nThe paths are optional; if not given . is used.")
group = parser.add_argument_group("Options")
group.add_argument("-path", default = ".", help = argparse.SUPPRESS, metavar = "")
group.add_argument("-m", "--modified", default = False,
help = "show last modified date/time [default: off]",
metavar = "")
group.add_argument("-o ORDER", "--order=ORDER", nargs = 2, default = "name",
help = "order by ('name', 'n', 'modified', 'm', 'size', 's')\n[default: name]",
metavar = "")
group.add_argument("-r", "--recursive", default = False,
help = "recurse into subdirectories [default: off]",
metavar = "")
group.add_argument("-s", "--sizes", default = False,
help = "show sizes [default: off]", metavar = "")
args = parser.parse_args()
return args
When called in the following manner "LS.py -h" it produces the following output:
usage: LS.py [options] [path1 [path2 [...pathN]]]
The paths are optional; if not given . is used.
optional arguments:
-h, --help show this help message and exit
Options:
-m , --modified show last modified date/time [default: off]
-o ORDER , --order=ORDER
order by ('name', 'n', 'modified', 'm', 'size', 's')
[default: name]
-r , --recursive recurse into subdirectories [default: off]
-s , --sizes show sizes [default: off]
My question: Is there a way to move the default help argument into a group such as Options? Also, I can't seem to find a way to remove the space before the commas in the Options arguments. The ideal output is:
Usage: ls.py [options] [path1 [path2 [...pathN]]]
The paths are optional; if not given . is used.
Options:
-h, --help show this help message and exit
-m, --modified show last modified date/time [default: off]
-o ORDER, --order=ORDER
order by ('name', 'n', 'modified', 'm', 'size', 's')
[default: name]
-r, --recursive recurse into subdirectories [default: off]
-s, --sizes show sizes [default: off]
回答1:
You can use add_help=False to disable the built-in help command and add your own instead, using action="help" (thanks @mgilson!)
To get rid of the spaces, don't set metavar to an empty string. Your options should be specified using action="store_true" to make them true (argument-less) options:
import argparse
parser = argparse.ArgumentParser(prog="LS.py",
usage="%(prog)s [options] [paths...]\nThe paths are optional; if not given . is used.",
add_help=False)
group = parser.add_argument_group("Options")
group.add_argument("-h", "--help", action="help", help="show this help message and exit")
group.add_argument("-path", default=".", help=argparse.SUPPRESS)
group.add_argument("-m", "--modified", action="store_true",
help="show last modified date/time")
group.add_argument("-o", "--order", nargs=1, default="name",
help="sort order (n[ame], m[odified], s[ize])\n[default: name]")
group.add_argument("-r", "--recursive", action="store_true",
help="recurse into subdirectories")
group.add_argument("-s", "--sizes", action="store_true",
help="show sizes")
args = parser.parse_args()
Output:
Options:
-h, --help show this help message and exit
-m, --modified show last modified date/time
-o ORDER, --order ORDER
sort order (n[ame], m[odified], s[ize]) [default:
name]
-r, --recursive recurse into subdirectories
-s, --sizes show sizes
回答2:
Sure you can do that. The trick is to just add add_help=False the the ArgumentParser constructor and then add your own help action to the group:
import argparse
parser = argparse.ArgumentParser(prog = "LS.py",
usage = "%(prog)s [options] [path1 [path2 [...pathN]]]\nThe paths are optional; if not given . is used.",
add_help=False)
group = parser.add_argument_group("Options")
group.add_argument("-path", default = ".", help = argparse.SUPPRESS, metavar = "")
group.add_argument("-m", "--modified", default = False,
help = "show last modified date/time [default: off]",
metavar = "")
group.add_argument("-o ORDER", "--order=ORDER", nargs = 2, default = "name",
help = "order by ('name', 'n', 'modified', 'm', 'size', 's')\n[default: name]",
metavar = "")
group.add_argument("-h", "--help", action='help', help='print this fabulous help message')
group.add_argument("-r", "--recursive", default = False,
help = "recurse into subdirectories [default: off]",
metavar = "")
group.add_argument("-s", "--sizes", default = False,
help = "show sizes [default: off]", metavar = "")
args = parser.parse_args()
回答3:
To condense and simplify a bit upon the previous answer by nneonneo, you can have:
import argparse
parser = argparse.ArgumentParser(prog="LS.py",
usage="%(prog)s [options] [paths...]\nThe paths are optional; if not given . is used.",
add_help=False)
add_arg = parser.add_argument_group("Options").add_argument
add_arg("-h", "--help", action="help", help="show this help message and exit")
add_arg("-path", default=".", help=argparse.SUPPRESS)
add_arg("-m", "--modified", action="store_true",
help="show last modified date/time")
add_arg("-o", "--order", nargs=1, default="name",
help="sort order (n[ame], m[odified], s[ize])\n[default: name]")
add_arg("-r", "--recursive", action="store_true",
help="recurse into subdirectories")
add_arg("-s", "--sizes", action="store_true",
help="show sizes")
args = parser.parse_args()
Basically, the slight variation from the previous answer is that it is not necessary to save group and then repeatedly call the the add_argument method on it.
来源：https://stackoverflow.com/questions/13075241/move-help-to-a-different-argument-group-in-python-argparse