Confusing syntax error for missing comma after import-as target

Bug report

Bug description:

Right now we have:

>>> import a as a  b
  File "<python-input-0>", line 1
    import a as a  b
                ^
SyntaxError: cannot use name as import target

>>> from x import a as a  b
  File "<python-input-1>", line 1
    from x import a as a  b
                       ^
SyntaxError: cannot use name as import target

This happens since these cases match these two rules.

One possible fix would be to add NAME to the list of not-matched tokens so that the current rules don't match this case.

However, I have an idea for a slightly nicer error. PR forthcoming.

cc @pablogsal @lysnikolaou @sobolevn

CPython versions tested on:

3.14, 3.15, CPython main branch

Operating systems tested on:

Linux

Linked PRs

• gh-146493

Reproduza os dois exemplos de import-as no Python REPL e, em seguida, inspecione as duas regras correspondentes em Grammar/python.gram próximas às linhas 1435 e 1439. Compare o diagnóstico resultante com o comportamento esperado descrito na issue; considera-se concluído quando o caso de vírgula ausente recebe um erro de sintaxe mais claro. Um PR vinculado já está indicado.