Remove ConverterKeywordDict alias in clinic.py

[sobolevn]

Context: python/mypy#16939 (comment)

New mypy version detected this typing problem: dict[str, TypeSet | bool] is not the correct type for **kwargs of str_converter.__init__:

CPython (Argument Clinic) (https://github.com/python/cpython)
+ Tools/clinic/clinic.py:4094: error: Argument 1 to "str_converter" has incompatible type "**dict[str, set[type[object]] | bool]"; expected "str"  [arg-type]
+ Tools/clinic/clinic.py:4094: error: Argument 1 to "str_converter" has incompatible type "**dict[str, set[type[object]] | bool]"; expected "Function"  [arg-type]
+ Tools/clinic/clinic.py:4094: error: Argument 1 to "str_converter" has incompatible type "**dict[str, set[type[object]] | bool]"; expected "str | None"  [arg-type]
+ Tools/clinic/clinic.py:4094: error: Argument 1 to "str_converter" has incompatible type "**dict[str, set[type[object]] | bool]"; expected "str | Literal[Sentinels.unspecified]"  [arg-type]
+ Tools/clinic/clinic.py:4094: error: Argument 1 to "str_converter" has incompatible type "**dict[str, set[type[object]] | bool]"; expected "bool"  [arg-type]

(the error message looks cryptic).

str_converter.__init__ has this type:

def __init__(self,
             # Positional args:
             name: str,
             py_name: str,
             function: Function,
             default: object = unspecified,
             *,  # Keyword only args:
             c_default: str | None = None,
             py_default: str | None = None,
             annotation: str | Literal[Sentinels.unspecified] = unspecified,
             unused: bool = False,
             **kwargs: Any
    ) -> None:

So, basically you can only say that **kwargs can be dict[str, Any].
This is why I removed this alias.

[AlexWaygood]

Or perhaps we could do something like this? It would be slightly less dynamic, meaning mypy would have a higher chance of understanding what we're doing here:

--- a/Tools/clinic/clinic.py
+++ b/Tools/clinic/clinic.py
@@ -4069,8 +4069,6 @@ def parse_arg(self, argname: str, displayname: str, *, limited_capi: bool) -> st
 # mapping from arguments to format unit *and* registers the
 # legacy C converter for that format unit.
 #
-ConverterKeywordDict = dict[str, TypeSet | bool]
-
 def r(format_unit: str,
       *,
       accept: TypeSet,
@@ -4086,12 +4084,10 @@ def r(format_unit: str,
         #
         # also don't add the converter for 's' because
         # the metaclass for CConverter adds it for us.
-        kwargs: ConverterKeywordDict = {}
         if accept != {str}:
-            kwargs['accept'] = accept
-        if zeroes:
-            kwargs['zeroes'] = True
-        added_f = functools.partial(str_converter, **kwargs)
+            added_f = functools.partial(str_converter, accept=accept)
+        else:
+            added_f = functools.partial(str_converter, zeroes=True)
         legacy_converters[format_unit] = added_f
 
     d = str_converter_argument_map

[sobolevn]

@AlexWaygood indeed! This is a better way! 👍

[sobolevn]

except, it is a bit more complex. There might be two conditions at once:

• accept != {str}
• zeroes

[AlexWaygood]

except, it is a bit more complex. There might be two conditions at once:

* `accept != {str}`

* `zeroes`

Ah shoot, yes, it's not a 1:1 rewrite, is it. The original doesn't use else:. Let's go with your way for now then :)

[AlexWaygood]

Thanks!