feat: ✨ Allow for functools.partial and functions returning an awaitable as autocomplete

CHANGELOG.md

@@ -36,6 +36,9 @@ These changes are available on the `master` branch, but have not yet been releas
   `Permissions.use_external_sounds`, and
   `Permissions.view_creator_monetization_analytics`.
   ([#2620](https://github.com/Pycord-Development/pycord/pull/2620))
+- Added the ability to use functions with any number of optional arguments, and
+  functions returning an awaitable as `Option.autocomplete`
+  ([#2669](https://github.com/Pycord-Development/pycord/pull/2669)).
 
 ### Fixed
 

discord/commands/core.py

@@ -1095,13 +1095,13 @@ async def invoke_autocomplete_callback(self, ctx: AutocompleteContext):
                 ctx.value = op.get("value")
                 ctx.options = values
 
-                if len(inspect.signature(option.autocomplete).parameters) == 2:
+                if option.autocomplete._is_instance_method:
                     instance = getattr(option.autocomplete, "__self__", ctx.cog)
                     result = option.autocomplete(instance, ctx)
                 else:
                     result = option.autocomplete(ctx)
 
-                if asyncio.iscoroutinefunction(option.autocomplete):
+                if inspect.isawaitable(result):
                     result = await result
 
                 choices = [

discord/commands/options.py

@@ -26,8 +26,9 @@
 
 import inspect
 import logging
+from collections.abc import Awaitable, Callable, Iterable
 from enum import Enum
-from typing import TYPE_CHECKING, Literal, Optional, Type, Union
+from typing import TYPE_CHECKING, Any, Literal, Optional, Type, TypeVar, Union
 
 from ..abc import GuildChannel, Mentionable
 from ..channel import (
@@ -39,13 +40,14 @@
     Thread,
     VoiceChannel,
 )
-from ..commands import ApplicationContext
+from ..commands import ApplicationContext, AutocompleteContext
 from ..enums import ChannelType
 from ..enums import Enum as DiscordEnum
 from ..enums import SlashCommandOptionType
 from ..utils import MISSING, basic_autocomplete
 
 if TYPE_CHECKING:
+    from ..cog import Cog
     from ..ext.commands import Converter
     from ..member import Member
     from ..message import Attachment
@@ -71,6 +73,25 @@
         Type[DiscordEnum],
     ]
 
+    AutocompleteReturnType = Union[
+        Iterable["OptionChoice"], Iterable[str], Iterable[int], Iterable[float]
+    ]
+    T = TypeVar("T", bound=AutocompleteReturnType)
+    MaybeAwaitable = Union[T, Awaitable[T]]
+    AutocompleteFunction = Union[
+        Callable[[AutocompleteContext], MaybeAwaitable[AutocompleteReturnType]],
+        Callable[[Cog, AutocompleteContext], MaybeAwaitable[AutocompleteReturnType]],
+        Callable[
+            [AutocompleteContext, Any],  # pyright: ignore [reportExplicitAny]
+            MaybeAwaitable[AutocompleteReturnType],
+        ],
+        Callable[
+            [Cog, AutocompleteContext, Any],  # pyright: ignore [reportExplicitAny]
+            MaybeAwaitable[AutocompleteReturnType],
+        ],
+    ]
+
+
 __all__ = (
     "ThreadOption",
     "Option",
@@ -146,15 +167,6 @@ class Option:
     max_length: Optional[:class:`int`]
         The maximum length of the string that can be entered. Must be between 1 and 6000 (inclusive).
         Only applies to Options with an :attr:`input_type` of :class:`str`.
-    autocomplete: Optional[Callable[[:class:`.AutocompleteContext`], Awaitable[Union[Iterable[:class:`.OptionChoice`], Iterable[:class:`str`], Iterable[:class:`int`], Iterable[:class:`float`]]]]]
-        The autocomplete handler for the option. Accepts a callable (sync or async)
-        that takes a single argument of :class:`AutocompleteContext`.
-        The callable must return an iterable of :class:`str` or :class:`OptionChoice`.
-        Alternatively, :func:`discord.utils.basic_autocomplete` may be used in place of the callable.
-
-        .. note::
-
-            Does not validate the input value against the autocomplete results.
     channel_types: list[:class:`discord.ChannelType`] | None
         A list of channel types that can be selected in this option.
         Only applies to Options with an :attr:`input_type` of :class:`discord.SlashCommandOptionType.channel`.
@@ -272,6 +284,7 @@ def __init__(
         )
         self.default = kwargs.pop("default", None)
 
+        self._autocomplete: AutocompleteFunction | None = None
         self.autocomplete = kwargs.pop("autocomplete", None)
         if len(enum_choices) > 25:
             self.choices: list[OptionChoice] = []
@@ -390,6 +403,43 @@ def to_dict(self) -> dict:
     def __repr__(self):
         return f"<discord.commands.{self.__class__.__name__} name={self.name}>"
 
+    @property
+    def autocomplete(self) -> AutocompleteFunction | None:
+        """
+        The autocomplete handler for the option. Accepts a callable (sync or async)
+        that takes a single required argument of :class:`AutocompleteContext` or two arguments
+        of :class:`discord.Cog` (being the command's cog) and :class:`AutocompleteContext`.
+        The callable must return an iterable of :class:`str` or :class:`OptionChoice`.
+        Alternatively, :func:`discord.utils.basic_autocomplete` may be used in place of the callable.
+
+        Returns
+        -------
+            Optional[AutocompleteFunction]
+
+        .. versionchanged:: 2.7
+
+        .. note::
+            Does not validate the input value against the autocomplete results.
+        """
+        return self._autocomplete
+
+    @autocomplete.setter
+    def autocomplete(self, value: AutocompleteFunction | None) -> None:
+        self._autocomplete = value
+        # this is done here so it does not have to be computed every time the autocomplete is invoked
+        if self._autocomplete is not None:
+            self._autocomplete._is_instance_method = (  # pyright: ignore [reportFunctionMemberAccess]
+                sum(
+                    1
+                    for param in inspect.signature(
+                        self._autocomplete
+                    ).parameters.values()
+                    if param.default == param.empty  # pyright: ignore[reportAny]
+                    and param.kind not in (param.VAR_POSITIONAL, param.VAR_KEYWORD)
+                )
+                == 2
+            )
+
 
 class OptionChoice:
     """

examples/app_commands/slash_partial_autocomplete.py

@@ -0,0 +1,49 @@
+from functools import partial
+from os import getenv
+
+from dotenv import load_dotenv
+
+import discord
+from discord.ext import commands
+
+load_dotenv()
+
+bot = discord.Bot()
+
+fruits = ["Apple", "Banana", "Orange"]
+vegetables = ["Carrot", "Lettuce", "Potato"]
+
+
+async def food_autocomplete(
+    ctx: discord.AutocompleteContext, food_type: str
+) -> list[discord.OptionChoice]:
+    items = fruits if food_type == "fruit" else vegetables
+    return [
+        discord.OptionChoice(name=item)
+        for item in items
+        if ctx.value.lower() in item.lower()
+    ]
+
+
+class FoodCog(commands.Cog):
+    @commands.slash_command(name="fruit")
+    @discord.option(
+        "choice",
+        "Pick a fruit",
+        autocomplete=partial(food_autocomplete, food_type="fruit"),
+    )
+    async def get_fruit(self, ctx: discord.ApplicationContext, choice: str):
+        await ctx.respond(f'You picked "{choice}"')
+
+    @commands.slash_command(name="vegetable")
+    @discord.option(
+        "choice",
+        "Pick a vegetable",
+        autocomplete=partial(food_autocomplete, food_type="vegetable"),
+    )
+    async def get_vegetable(self, ctx: discord.ApplicationContext, choice: str):
+        await ctx.respond(f'You picked "{choice}"')
+
+
+bot.add_cog(FoodCog())
+bot.run(getenv("TOKEN"))