types._cell_factory is exposed, unlike other helpers

[sobolevn]

types.py module has different helpers to get their types, like async def _c(): pass to get coroutine type or def _g(): yield 1 to get generator type, etc.

It has has these line to get CellType:

cpython/Lib/types.py

Lines 18 to 23 in 9625de6

	def _cell_factory():
	a = 1
	def f():
	nonlocal a
	return f.__closure__[0]
	CellType = type(_cell_factory())

Afterward, all helpers are deleted, except _cell_factory, which I think should be fixed. It is not good to expose such implementation details.

And this line agrees with me:

cpython/Lib/types.py

Line 63 in 9625de6

del sys, _f, _g, _C, _c, _ag # Not for export

Related:

• bpo-36091: remove reference to async generator in Lib/types.py #11996
• bpo-35911: add cell constructor #11771