parse_args in completers not populated when Action is used.

[RiccySidoli]

When defining a custom Completion and Action the parsed_args for Completer call are empty. This means I cannot use first completiion in second.

I am using macos 26.1 (Tahoe), Python 3.14.0, zsh (macOS)

Code:

#!/usr/bin/env python3

PYTHON_ARGCOMPLETE_OK

import os,sys
import argparse, argcomplete
from argcomplete.completers import FilesCompleter, ChoicesCompleter, BaseCompleter
from argcomplete import warn

class ArtistAction(argparse.Action):
""" Custom action to get artist id from artist name """
def call(self, parser, namespace, values, option_string=None):
""" Custom action to set arg to artist id based on artist name.
"""
warn(f"ArtistAction Entry: namespace={namespace}")
setattr(namespace, "test_artist", 10)
setattr(namespace,"artist", values)
warn(f"ArtistAction Exit: namespace={namespace}")

class AlbumAction(argparse.Action):
""" Custom action to get album id from album name """
def call(self, parser, namespace, values, option_string=None):
""" Custom action to set arg to album id based on album name.
"""
warn(f"AlbumAction Entry: namespace={namespace}")
setattr(namespace,"test_album", 10)
setattr(namespace,"album", values)
warn(f"AlbumAction Exit: namespace={namespace}")

class ArtistCompleter(BaseCompleter):
""" Completer for artist names """
def call(self, prefix, parser, parsed_args, **kwargs):
""" Complete artist names """
warn(f'ArtistCompleter: parsed_args={parsed_args}')
return ['Artist1', 'Artist2', 'Artist3']

class AlbumCompleter(BaseCompleter):
""" Completer for album names """
def call(self, prefix, parser, parsed_args, **kwargs):
""" Complete album names """
warn(f'AlbumCompleter: parsed_args={parsed_args}')
return ['Album1', 'Album2', 'Album3']

def get_args():

warn("Creating argument parser")
parser = argparse.ArgumentParser(description='Search for an artist on Spotify',formatter_class=argparse.ArgumentDefaultsHelpFormatter)

warn("Adding arguments")

# parser.add_argument('artist',  help='An Artist').completer=ArtistCompleter()
# parser.add_argument('album',  help='An Album').completer=AlbumCompleter()
# parser.add_argument('artist', action=ArtistAction, help='An Artist')
# parser.add_argument('album', action=AlbumAction, help='An Album')
parser.add_argument('artist', action=ArtistAction, help='An Artist').completer=ArtistCompleter()
parser.add_argument('album', action=AlbumAction, help='An Album').completer=AlbumCompleter()

#argcomplete.autocomplete(parser, always_complete_options=False)
warn("Calling argcomplete.autocomplete")

a = argparse.Namespace()
setattr(a, "check", 1)

argcomplete.autocomplete(parser)

#setattr(parser, 'sp', sp)    # Add Spotify object to parser for access in actions
return parser.parse_args(namespace=a)

def test_search_artist():

args = get_args()

print(args)

def main():
test_search_artist()

if name == "main":
main()

results in:

ArtistCompleter: parsed_args=Namespace(artist=None, album=None)
test_completions.py
ArtistCompleter: parsed_args=Namespace(artist=None, album=None)
--help -h --test_completions.py Artist3
AlbumCompleter: parsed_args=Namespace(artist=None, album=None)
test_completions.py Artist3
AlbumCompleter: parsed_args=Namespace(artist=None, album=None)
--help -h -- shtest_completions.py Artist3 Album2

Creating argument parser

Adding arguments

Calling argcomplete.autocomplete

ArtistAction Entry: namespace=Namespace(check=1, artist=None, album=None)

ArtistAction Exit: namespace=Namespace(check=1, artist='Artist3', album=None, test_artist=10)

AlbumAction Entry: namespace=Namespace(check=1, artist='Artist3', album=None, test_artist=10)

AlbumAction Exit: namespace=Namespace(check=1, artist='Artist3', album='Album2', test_artist=10, test_album=10)
Namespace(check=1, artist='Artist3', album='Album2', test_artist=10, test_album=10)

[kislyuk]

Thank you for your interest in argcomplete. I don't have the time to debug what exactly went wrong with your script, but I was able to confirm that partial parse results are passed to completers as expected using the following test case:

#!/usr/bin/env python
#PYTHON_ARGCOMPLETE_OK
import argparse, argcomplete

class C:
    def __call__(self, **kwargs):
        argcomplete.warn("Completer called with args:", kwargs)
        return ["1", "2", "3"]

def main():
    parser = argparse.ArgumentParser()
    action = parser.add_argument("--test", type=int)
    action.completer=C()
    action2 = parser.add_argument("--test2", type=int)
    action2.completer=C()
    argcomplete.autocomplete(parser)
    args = parser.parse_args()
    print(args)

if __name__ == "__main__":
    main()

>./t.py --test 1 --test2  <TAB>
Completer called with args: {'prefix': '', 'action': IntrospectAction(option_strings=['--test2'], dest='test2', nargs=None, const=None, default=None, type=<class 'int'>, choices=None, required=False, help=None, metavar=None), 'parser': MonkeyPatchedIntrospectiveArgumentParser(prog='t.py', usage=None, description=None, formatter_class=<class 'argparse.HelpFormatter'>, conflict_handler='error', add_help=True), 'parsed_args': Namespace(test=1, test2=None)}

Completer called with args: {'prefix': '', 'action': IntrospectAction(option_strings=['--test2'], dest='test2', nargs=None, const=None, default=None, type=<class 'int'>, choices=None, required=False, help=None, metavar=None), 'parser': MonkeyPatchedIntrospectiveArgumentParser(prog='t.py', usage=None, description=None, formatter_class=<class 'argparse.HelpFormatter'>, conflict_handler='error', add_help=True), 'parsed_args': Namespace(test=1, test2=None)}
                        ./t.py --test 1 --test2 
Completing `./t.py'

I am going to close this issue for now, since it doesn't seem to involve a bug with argcomplete. If you need help, please provide a precise, complete reproduction of the intended vs. expected behavior.

[RiccySidoli]

Hi Your script works but is not the same test case as mine. In mine I have defined a custom Action and when I use that parsed_args does not get filled in - try this #!/usr/bin/env python3 #PYTHON_ARGCOMPLETE_OK import argparse, argcomplete class C: def __call__(self, **kwargs): argcomplete.warn("Completer called with args:", kwargs) return ["1", "2", "3"] class A(argparse.Action): def __init__(self, option_strings, dest, nargs=None, **kwargs): if nargs is not None: raise ValueError("nargs not allowed") super().__init__(option_strings, dest, **kwargs) def __call__(self, parser, namespace, values, option_string=None): print('%r %r %r' % (namespace, values, option_string)) setattr(namespace, self.dest, values) def main(): parser = argparse.ArgumentParser() action = parser.add_argument("--test", action = A) action.completer=C() action2 = parser.add_argument("--test2", action = A) action2.completer=C() argcomplete.autocomplete(parser) args = parser.parse_args() print(args) if __name__ == "__main__": main() With output Completer called with args: {'prefix': '', 'action': IntrospectAction(option_strings=['--test'], dest='test', nargs=None, const=None, default=None, type=None, choices=None, required=False, help=None, metavar=None, deprecated=False), 'parser': MonkeyPatchedIntrospectiveArgumentParser(prog='tester.py', usage=None, description=None, formatter_class=<class 'argparse.HelpFormatter'>, conflict_handler='error', add_help=True), 'parsed_args': Namespace(test=None, test2=None)} tester.py --test Completer called with args: {'prefix': '', 'action': IntrospectAction(option_strings=['--test'], dest='test', nargs=None, const=None, default=None, type=None, choices=None, required=False, help=None, metavar=None, deprecated=False), 'parser': MonkeyPatchedIntrospectiveArgumentParser(prog='tester.py', usage=None, description=None, formatter_class=<class 'argparse.HelpFormatter'>, conflict_handler='error', add_help=True), 'parsed_args': Namespace(test=None, test2=None)} 3 tester.py --test 3 --test2 Completer called with args: {'prefix': '', 'action': IntrospectAction(option_strings=['--test2'], dest='test2', nargs=None, const=None, default=None, type=None, choices=None, required=False, help=None, metavar=None, deprecated=False), 'parser': MonkeyPatchedIntrospectiveArgumentParser(prog='tester.py', usage=None, description=None, formatter_class=<class 'argparse.HelpFormatter'>, conflict_handler='error', add_help=True), 'parsed_args': Namespace(test=None, test2=None)} tester.py --test 3 --test2 Completer called with args: {'prefix': '', 'action': IntrospectAction(option_strings=['--test2'], dest='test2', nargs=None, const=None, default=None, type=None, choices=None, required=False, help=None, metavar=None, deprecated=False), 'parser': MonkeyPatchedIntrospectiveArgumentParser(prog='tester.py', usage=None, description=None, formatter_class=<class 'argparse.HelpFormatter'>, conflict_handler='error', add_help=True), 'parsed_args': Namespace(test=None, test2=None)} 3 tester.py --test 3 --test2 2 Namespace(test=None, test2=None) '3' '--test' Namespace(test='3', test2=None) '2' '--test2' Namespace(test='3', test2='2’) On 23 Nov 2025, at 18:44, Andrey Kislyuk ***@***.***> wrote: [https://avatars.githubusercontent.com/u/862013?s=20&v=4]kislyuk left a comment (kislyuk/argcomplete#548)<#548 (comment)> Thank you for your interest in argcomplete. I don't have the time to debug what exactly went wrong with your script, but I was able to confirm that partial parse results are passed to completers as expected using the following test case: #!/usr/bin/env python #PYTHON_ARGCOMPLETE_OK import argparse, argcomplete class C: def __call__(self, **kwargs): argcomplete.warn("Completer called with args:", kwargs) return ["1", "2", "3"] def main(): parser = argparse.ArgumentParser() action = parser.add_argument("--test", type=int) action.completer=C() action2 = parser.add_argument("--test2", type=int) action2.completer=C() argcomplete.autocomplete(parser) args = parser.parse_args() print(args) if __name__ == "__main__": main()

./t.py --test 1 --test2 <TAB>

Completer called with args: {'prefix': '', 'action': IntrospectAction(option_strings=['--test2'], dest='test2', nargs=None, const=None, default=None, type=<class 'int'>, choices=None, required=False, help=None, metavar=None), 'parser': MonkeyPatchedIntrospectiveArgumentParser(prog='t.py', usage=None, description=None, formatter_class=<class 'argparse.HelpFormatter'>, conflict_handler='error', add_help=True), 'parsed_args': Namespace(test=1, test2=None)} Completer called with args: {'prefix': '', 'action': IntrospectAction(option_strings=['--test2'], dest='test2', nargs=None, const=None, default=None, type=<class 'int'>, choices=None, required=False, help=None, metavar=None), 'parser': MonkeyPatchedIntrospectiveArgumentParser(prog='t.py', usage=None, description=None, formatter_class=<class 'argparse.HelpFormatter'>, conflict_handler='error', add_help=True), 'parsed_args': Namespace(test=1, test2=None)} ./t.py --test 1 --test2 Completing `./t.py' I am going to close this issue for now, since it doesn't seem to involve a bug with argcomplete. If you need help, please provide a precise, complete reproduction of the intended vs. expected behavior. — Reply to this email directly, view it on GitHub<#548 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/ABZAQVUAF735GIPETO7IOGL36H577AVCNFSM6AAAAACM5HGG4KVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTKNRYGIZTCMZYG4>. You are receiving this because you authored the thread.Message ID: ***@***.***>