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import argparse

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parser = argparse.ArgumentParser()
parser.parse_args()

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usage: __main__.py [-h]
__main__.py: error: unrecognized arguments: -f /run/user/1006/jupyter/kernel-ce6cfb61-acb9-40bf-a59b-ff6e1c1eacae.json
An exception has occurred, use %tb to see the full traceback.
SystemExit: 2

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import sys
sys.argv

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['/home/liu/anaconda2/lib/python2.7/site-packages/ipykernel/__main__.py',
'-f',
'/run/user/1006/jupyter/kernel-ce6cfb61-acb9-40bf-a59b-ff6e1c1eacae.json']

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parser.parse_args??
parser.parse_known_args??

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Signature: parser.parse_args(args=None, namespace=None)
Source:
def parse_args(self, args=None, namespace=None):
args, argv = self.parse_known_args(args, namespace)
if argv:
msg = _('unrecognized arguments: %s')
self.error(msg % ' '.join(argv))
return args
File:
/home/liu/anaconda2/lib/python2.7/argparse.py
Type:
instancemethod
Signature: parser.parse_known_args(args=None, namespace=None)
Source:
def parse_known_args(self, args=None, namespace=None):
if args is None:
# args default to the system args
args = _sys.argv[1:]
else:
# make sure that args are mutable
args = list(args)
# default Namespace built from parser defaults
if namespace is None:
namespace = Namespace()
# add any action defaults that aren't present
for action in self._actions:
if action.dest is not SUPPRESS:
if not hasattr(namespace, action.dest):
if action.default is not SUPPRESS:
setattr(namespace, action.dest, action.default)
# add any parser defaults that aren't present
for dest in self._defaults:
if not hasattr(namespace, dest):
setattr(namespace, dest, self._defaults[dest])
# parse the arguments and exit if there are any errors
try:
namespace, args = self._parse_known_args(args, namespace)
if hasattr(namespace, _UNRECOGNIZED_ARGS_ATTR):
args.extend(getattr(namespace, _UNRECOGNIZED_ARGS_ATTR))
delattr(namespace, _UNRECOGNIZED_ARGS_ATTR)
return namespace, args
except ArgumentError:
err = _sys.exc_info()[1]
self.error(str(err))
File:
/home/liu/anaconda2/lib/python2.7/argparse.py
Type:
instancemethod

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parser = argparse.ArgumentParser()
parser.add_argument("--verbosity", help="increase output verbosity")
args = parser.parse_args(args=[])
print(args)

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Namespace(verbosity=None)