python / cpython

…GH-19846)

It was positional-only de facto: documentation and two implementations
used three different name.

Before this commit, if an exception was active inside a generator
when calling gen.throw(), that exception was lost (i.e. there was
no implicit exception chaining).  This commit fixes that by
setting exc.__context__ when calling gen.throw(exc).

I can add another commit with the new test case I wrote to verify that the warning was being printed before my change, stopped printing after my change, and that the function does not return null after my change.

Automerge-Triggered-By: @brettcannon

Otherwise we leave a dangling pointer to free'd memory. If we
then initialize a new interpreter in the same process and call
PyImport_ExtendInittab, we will (likely) crash when calling
PyMem_RawRealloc(inittab_copy, ...) since the pointer address
is bogus.

Automerge-Triggered-By: @brettcannon

…H-19831)

…9839)

This commit makes both APIs more consistent by doing the following:
- Remove the `PyPegen_CodeObjectFrom*` functions, which weren't used 
  and will probably not be needed. Functions like `Py_CompileStringObject`
  can be used instead.
- Include a `const char *filename` parameter in `PyPegen_ASTFromString`.
- Rename `PyPegen_ASTFromFile` to `PyPegen_ASTFromFilename`, because
  its signature is not the same with `PyParser_ASTFromFile`.

…ser (GH-19837)

…H-19782)

Automerge-Triggered-By: @vstinner

An isolated subinterpreter cannot spawn threads, spawn a child
process or call os.fork().

* Add private _Py_NewInterpreter(isolated_subinterpreter) function.
* Add isolated=True keyword-only parameter to
  _xxsubinterpreters.create().
* Allow again os.fork() in "non-isolated" subinterpreters.

…9767)

`ast.parse` and `compile` support a `feature_version` parameter that
tells the parser to parse the input string, as if it were written in
an older Python version.
The `feature_version` is propagated to the tokenizer, which uses it
to handle the three different stages of support for `async` and
`await`. Additionally, it disallows the following at parser level:
- The '@' operator in < 3.5
- Async functions in < 3.5
- Async comprehensions in < 3.6
- Underscores in numeric literals in < 3.6
- Await expression in < 3.5
- Variable annotations in < 3.6
- Async for-loops in < 3.5
- Async with-statements in < 3.5
- F-strings in < 3.6

Closes we-like-parsers#124.

Replace TestFailed with support.TestFailed.

Bug spotted by pyflakes.

Cast Py_ARRAY_LENGTH() size_t to int explicitly.

GH-19811)" (#19821)

This reverts commit 2514a63.

)

Before this commit, if an exception was active inside a generator
when calling gen.throw(), then that exception was lost (i.e. there
was no implicit exception chaining).  This commit fixes that.

This implements full support for # type: <type> comments, # type: ignore <stuff> comments, and the func_type parsing mode for ast.parse() and compile().

Closes we-like-parsers#95.

(For now, you need to use the master branch of mypy, since another issue unique to 3.9 had to be fixed there, and there's no mypy release yet.)

The only thing missing is `feature_version=N`, which is being tracked in we-like-parsers#124.

…H-19742)

* bpo-40394 - difflib.SequenceMatched.find_longest_match default args

Added default args to find_longest_match, as well as related tests.