Bug report

argparse doesn't convert hyphens to underscores in positional arguments

import argparse

parser = argparse.ArgumentParser()

parser.add_argument('hyp-hens1')
parser.add_argument('--hyp-hens2')

args = parser.parse_args()

print(args.hyp_hens2)
print(args.hyp_hens1)

Should run fine when first arg is provided, instead

Traceback (most recent call last):
  File "/app/output.s", line 11, in <module>
    print(args.hyp_hens1)
          ^^^^^^^^^^^^^^
AttributeError: 'Namespace' object has no attribute 'hyp_hens1'. Did you mean: 'hyp-hens1'?

Your environment

• CPython versions tested on: 3.10.8
• Operating system and architecture: Linux x86