Signature for NamedTuple in typing.pyi does not match typing.py

[gribbg]

The signature in typing.pyi has extra fields verbose and rename, which are not in typing.py. From typing.pyi:

def __init__(self, typename: str, fields: Iterable[Tuple[str, Any]] = ..., *,
             verbose: bool = ..., rename: bool = ..., **kwargs: Any) -> None: ...

From typing.py:

def __new__(self, typename, fields=None, **kwargs):

Which can also be seen in this example:

>>typing.NamedTuple('Example', verbose=bool, rename=bool).__annotations__
OrderedDict([('verbose', <class 'bool'>), ('rename', <class 'bool'>)])

Unsurprisingly, passing verbose=True (as implied by typing.pyi) causes an exception:

typing.NamedTuple('Example', verbose=True, other_field=int).__annotations__
 Traceback (most recent call last):
  File "<input>", line 1, in <module>
  File "C:\Program Files\Python37\lib\typing.py", line 1411, in __new__
    return _make_nmtuple(typename, fields)
  File "C:\Program Files\Python37\lib\typing.py", line 1326, in _make_nmtuple
    types = [(n, _type_check(t, msg)) for n, t in types]
  File "C:\Program Files\Python37\lib\typing.py", line 1326, in <listcomp>
    types = [(n, _type_check(t, msg)) for n, t in types]
  File "C:\Program Files\Python37\lib\typing.py", line 139, in _type_check
    raise TypeError(f"{msg} Got {arg!r:.100}.")
 TypeError: NamedTuple('Name', [(f0, t0), (f1, t1), ...]); each t must be a type Got True.

[gribbg]

See also issue38191 which is changing the signature of NamedTuple to:

'($cls, typename, fields=None, /, **kwargs)'

[gvanrossum]

Let's delete verbose and rename (I guess they were from some unimplemented idea?) and rename the other positional arguments to use the __private format, which PEP 484 gives the special meaning of "positional only". (We can't use the newfangled '/' syntax yet because not all tools reading .pyi files have a Python 3.8-capable parser.)

Can you submit a PR? Also please do the same for TypedDict, then your PR will close both issues.

[gribbg]

verbose and rename are part of collections.namedtuple, so I assume they came over from there when NamedTuple was first created.

[gvanrossum]

Oh, interesting. But since typing.NamedTuple doesn't support them, they should not be in the stubs.

[srittau]

PR welcome!