The `allow_abbrev` option for ArgumentParser is documented and intended to disable support for unique prefixes of --options, which may sometimes be ambiguous due to deferred parsing.
However, the initial implementation also broke parsing of grouped short flags, such as `-ab` meaning `-a -b` (or `-a=b`). Checking the argument for a leading `--` before rejecting it fixes this.
This was prompted by pytest-dev/pytestGH-5469, so a backport to at least 3.8 would be great 😄
And this is my first PR to CPython, so please let me know if I've missed anything!
https://bugs.python.org/issue26967
(cherry picked from commit dffca9e925)
Co-authored-by: Zac Hatfield-Dodds <Zac-HD@users.noreply.github.com>
There is a possibility that someone (like me) accidentally will omit parentheses with `FileType` arguments after `FileType`, and parser will contain wrong file until someone will try to use it.
Example:
```python
parser = argparse.ArgumentParser()
parser.add_argument('-x', type=argparse.FileType)
```
https://bugs.python.org/issue37150
(cherry picked from commit 03d5831a2d)
Co-authored-by: zygocephalus <grrrr@protonmail.com>
- bugfix and test for fragile metavar handling in argparse (see
bpo-24089, bpo-14046, bpo-25058, bpo-11874)
- also fixes some incorrect tests that did not make 1-element tuples correctly
bpo-26510 in 3.7.0a2 changed the behavior of argparse to make
subparsers required by default, returning to the behavior of 2.7
and 3.2. The behavior was changed in 3.3 to be no longer required.
While it might make more sense to have the default to required,
compatibility with 3.3 through 3.6 is probably less disruptive
than trying to reintroduce compatibility with 2.7 at this point.
This change restores the 3.6 behavior.
This adds support for parsing a command line where options and positionals are intermixed as is common in many unix commands. This is paul.j3's patch with a few tweaks.
Output of func(*args) stored in the next line:
item_help = join([func(*args) for func, args in self.items])
_Section.items only used by HelpFormatter._add_item() and it looks
like it doesn't have any side effects.
Patch by Yogesh Chaudhari.
