Description

ppaez

opened on Nov 23, 2022

Issue body actions

Documentation

The example that shows the use of sub-commands and set_defaults to dispatch a function for each sub-command, fails when there are no command line arguments:

AttributeError: 'Namespace' object has no attribute 'func'

A pull request is provided that adds one line to handle that case and an explanation in the documentation.

Linked PRs

• gh-99735: Handle no arguments when using sub-commands in argparse #99736
• gh-99735: Use required=True in argparse subparsers example #100927
• [3.11] gh-99735: Use required=True in argparse subparsers example (GH-100927) #102036
• [3.10] gh-99735: Use required=True in argparse subparsers example (GH-100927) #102037

Activity

1. ppaez

   added

   docsDocumentation in the Doc dirDocumentation in the Doc dir

   on Nov 23, 2022
2. ppaez

   changed the title [-]Handle no arguments when using sub-commands[/-] [+]Handle no arguments when using sub-commands in argparse[/+] on Nov 23, 2022
3. hpaulj commented on Dec 8, 2022

   

   hpaulj

   on Dec 8, 2022

   More actions

   Originally subparsers were required, so this issue did not come up. Because of a patching oversight, they are now optional, and we had to add the required parameter. I think this example would be better handled with a

    subparsers = parser.add_subparsers(required=True)
   

   Then we wouldn't have to define a func for the no-subparser case. Your patch works, but I think it adds too much to the text and example, detracting from the essence of what set_defaults adds.

   Whether we use set_defaults or not, the Namespace will have different attributes depending on what subparser (or none) the user invokes. The post parsing code has to handle that issue in one way or the other.
4. ppaez commented on Jan 10, 2023

   

   ppaez

   on Jan 10, 2023

   ContributorAuthor

   More actions

   I hadn't used the required=True parameter before. It is mentioned in the reference, but I didn't consider it. I also was not aware of those changes (bpo-9253 and bpo-26510), thanks for explaining them.

   PR #100927 has been created with only that change.
5. erlend-aasland

   added this to Argparse issueson Feb 1, 2023
6. hauntsaninja

   added a commit that references this issue on Feb 19, 2023

   gh-99735: Use required=True in argparse subparsers example (#100927)

   6aab56f
7. miss-islington

   added 4 commits that reference this issue on Feb 19, 2023

   pythongh-99735: Use required=True in argparse subparsers example (pyt…

   0288d9b

   pythongh-99735: Use required=True in argparse subparsers example (pyt…

   6f8c2be

   gh-99735: Use required=True in argparse subparsers example (GH-100927)

   4969903

   gh-99735: Use required=True in argparse subparsers example (GH-100927)

   f193fad
8. carljm

   added a commit that references this issue on Feb 20, 2023

   Merge branch 'main' into inlinecomp2

   9f0fc5b
9. erlend-aasland commented on Feb 21, 2023

   

   erlend-aasland

   on Feb 21, 2023

   Contributor

   More actions

   Can we close this issue?
10. erlend-aasland

    added

    pendingThe issue will be closed if no feedback is providedThe issue will be closed if no feedback is provided

    on Feb 21, 2023
11. erlend-aasland

    moved this to Doc issues in Argparse issueson Feb 21, 2023
12. hauntsaninja commented on Feb 21, 2023

    

    hauntsaninja

    on Feb 21, 2023

    Contributor

    More actions

    Yes we can! The backports had a hiccup, but they're all done now

    Reacted by Erlend E. Aasland
13. hauntsaninja

    closed this as completedon Feb 21, 2023
14. hauntsaninja

    removed

    pendingThe issue will be closed if no feedback is providedThe issue will be closed if no feedback is provided

    on Feb 21, 2023
15. erlend-aasland

    moved this from Doc issues to Done in Argparse issueson Feb 21, 2023
16. carljm

    added a commit that references this issue on Feb 22, 2023

    Merge branch 'main' into inlinecomp

    544b30c

Issue actions