✨ Implement .get and .index methods for Message

nonebot/adapters/_message.py

@@ -89,7 +89,7 @@ class MessageSegment(Mapping, abc.ABC, Generic[TM]):
         raise NotImplementedError
 
 
-class Message(List[TMS], Generic[TMS], abc.ABC):
+class Message(List[TMS], abc.ABC):
     """消息数组"""
 
     def __init__(
@@ -204,7 +204,7 @@ class Message(List[TMS], Generic[TMS], abc.ABC):
 
     def __getitem__(
         self: TM,
-        __args: Union[
+        args: Union[
             str,
             Tuple[str, int],
             Tuple[str, slice],
@@ -212,7 +212,7 @@ class Message(List[TMS], Generic[TMS], abc.ABC):
             slice,
         ],
     ) -> Union[TMS, TM]:
-        arg1, arg2 = __args if isinstance(__args, tuple) else (__args, None)
+        arg1, arg2 = args if isinstance(args, tuple) else (args, None)
         if isinstance(arg1, int) and arg2 is None:
             return super().__getitem__(arg1)
         elif isinstance(arg1, slice) and arg2 is None:
@@ -224,7 +224,22 @@ class Message(List[TMS], Generic[TMS], abc.ABC):
         elif isinstance(arg1, str) and isinstance(arg2, slice):
             return self.__class__([seg for seg in self if seg.type == arg1][arg2])
         else:
-            raise ValueError("Invalid arguments to __getitem__")
+            raise ValueError("Incorrect arguments to slice")
+
+    def index(self, value: Union[TMS, str], *args) -> int:
+        if isinstance(value, str):
+            first_segment = next((seg for seg in self if seg.type == value), None)  # type: ignore
+            return super().index(first_segment, *args)  # type: ignore
+        return super().index(value, *args)
+
+    def get(self: TM, type_: str, count: int) -> TM:
+        iterator = (seg for seg in self if seg.type == type_)
+        return self.__class__(
+            filter(
+                lambda seg: seg is not None,
+                (next(iterator) for _ in range(count)),
+            )
+        )
 
     def append(self: TM, obj: Union[str, TMS]) -> TM:
         """