argparse(自定義幫助格式化程式)
擴充套件版本的 https://stackoverflow.com/documentation/python/7701/cli-subcommands/25282/argparse-default-help-formatter 修復了幫助輸出。
import argparse
import sys
class CustomHelpFormatter(argparse.HelpFormatter):
def _format_action(self, action):
if type(action) == argparse._SubParsersAction:
# inject new class variable for subcommand formatting
subactions = action._get_subactions()
invocations = [self._format_action_invocation(a) for a in subactions]
self._subcommand_max_length = max(len(i) for i in invocations)
if type(action) == argparse._SubParsersAction._ChoicesPseudoAction:
# format subcommand help line
subcommand = self._format_action_invocation(action) # type: str
width = self._subcommand_max_length
help_text = ""
if action.help:
help_text = self._expand_help(action)
return " {:{width}} - {}\n".format(subcommand, help_text, width=width)
elif type(action) == argparse._SubParsersAction:
# process subcommand help section
msg = '\n'
for subaction in action._get_subactions():
msg += self._format_action(subaction)
return msg
else:
return super(CustomHelpFormatter, self)._format_action(action)
def check():
print("status")
return 0
parser = argparse.ArgumentParser(usage="sub <command>", add_help=False,
formatter_class=CustomHelpFormatter)
subparser = parser.add_subparsers(dest="cmd")
subparser.add_parser('status', help='show status')
subparser.add_parser('list', help='print list')
# custom help messge
parser._positionals.title = "commands"
# hack to show help when no arguments supplied
if len(sys.argv) == 1:
parser.print_help()
sys.exit(0)
args = parser.parse_args()
if args.cmd == 'list':
print('list')
elif args.cmd == 'status':
sys.exit(check())
沒有引數的輸出:
usage: sub <command>
commands:
status - show status
list - print list