gh-133850: Improved SyntaxError message for missing commas

[StanFromIreland]

Before:

>>> def func1(uhoh nocomma): pass
  File "<python-input-0>", line 1
    def func1(uhoh nocomma): pass
                  ^^^^^^^
SyntaxError: invalid syntax

Now:

>>> def func2(uhoh nocomma): pass
  File "<python-input-0>", line 1
    def func2(uhoh nocomma): pass
              ^^^^^^^^^^^^
SyntaxError: expected comma between parameters

• Issue: Improve SyntaxError message for missing commas #133850

[StanFromIreland]

@sobolevn Maybe you would be interested in reviewing?

[terryjreedy]

Grammar change works, but I cannot verify that is 'most correct' possible.

[bedevere-app]

A Python core developer has requested some changes be made to your pull request before we can consider merging it. If you could please address their requests along with any other requests in other reviews from core developers that would be appreciated.

Once you have made the requested changes, please leave a comment on this pull request containing the phrase I have made the requested changes; please review again. I will then notify any core developers who have left a review that you're ready for them to take another look at this pull request.

And if you don't make the requested changes, you will be put in the comfy chair!

Command and change request were wrong.

[terryjreedy]

Continues to work for me after simplification.