CODEWITHSUNDEEP
python-3.xjupyter-notebookargparse
nolwww
nolwww

Reputation: 1745

parser.add_argument and parser.parse_args() with jupyter

I'm trying to run some code with a jupyter notebook, but from the beginning, I have issues.

Indeed, it looks like I can't use these commands:

parser.add_argument('--lr', default=0.1, type=float, help='learning rate')
parser.add_argument('--resume', '-r', action='store_true', help='resume from checkpoint')

usage: ipykernel_launcher.py [-h] [--lr LR] [--resume] and ipykernel_launcher.py gives error: unrecognized arguments: -f

And:

args = parser.parse_args()

/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/argparse.py in parse_args(self, args, namespace)
   1750         if argv:
   1751             msg = _('unrecognized arguments: %s')
-> 1752             self.error(msg % ' '.join(argv))
   1753         return args
   1754 

/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/argparse.py in error(self, message)
   2499         self.print_usage(_sys.stderr)
   2500         args = {'prog': self.prog, 'message': message}
-> 2501         self.exit(2, _('%(prog)s: error: %(message)s\n') % args)

/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/argparse.py in exit(self, status, message)
   2486         if message:
   2487             self._print_message(message, _sys.stderr)
-> 2488         _sys.exit(status)
   2489 
   2490     def error(self, message):

SystemExit: 2

I've seen that some people already had this problem when trying to use jupyter and arg_parse, but I can't find an easy solution.

Thank you for your help!

Upvotes: 1

Views: 1780

Answers (1)

hpaulj
hpaulj

Reputation: 231665

When I launch a blank notebook and execute

import sys
sys.argv

I get

['/usr/local/lib/python3.6/dist-packages/ipykernel_launcher.py',
 '-f',
 '/run/user/1000/jupyter/kernel-b2d72478-6aaa-4206-9bf3-38fc1a0fd303.json']

parse_args() uses the sys.argv list that 'normally' comes from the shell that's calling your script. It is a list of the commandline strings.

The sys.argv that your script sees includes this -f argument, created by jupyter.

You could use parse_known_args() so that your parser doesn't raise this error. But you that won't help you get --lr or -r arguments - because jupyter's own parser will reject them.

The essence of the previous SO questions is that you can't provide commandline arguments to a notebooks.

Upvotes: 1

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