argparse.ArgumentParser silently swallows multiple -- (double dash)

Consider this:

import argparse
p = argparse.ArgumentParser()
p.add_argument('arg1', type=str)
p.add_argument('args', nargs='*')
p.parse_args(['foo', '--', '--bar', '--', 'com'])

The semantics of -- are to not attempt to parse the remaining command line options as parameters. Therefore, the expected output is:

Namespace(arg1='foo', args=['--bar', '--', 'com'])

However, the actual output is:

Namespace(arg1='foo', args=['--bar', 'com'])

In other words, the second -- has silently been dropped.

Interestingly enough, if the arg1 parameter is dropped, this works correctly:

p = argparse.ArgumentParser()
p.add_argument('args', nargs='*')
p.parse_args(['foo', '--', '--bar', '--', 'com'])
--> Namespace(args=['foo', '--bar', '--', 'com'])

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

argparse.ArgumentParser silently swallows multiple -- (double dash) #95468

Linked PRs

Metadata

Assignees

Labels

Fields

Projects

Milestone

Relationships

Development

Search code, repositories, users, issues, pull requests...

Uh oh!

argparse.ArgumentParser silently swallows multiple -- (double dash) #95468

Description

Linked PRs

Metadata

Metadata

Assignees

Labels

Fields

Projects

Milestone

Relationships

Development

Issue actions