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nonebot/command/argfilter/__init__.py

@@ -15,6 +15,21 @@ class ValidateError(ValueError):
 
 async def run_arg_filters(session: 'CommandSession',
                           arg_filters: List[ArgFilter_T]) -> None:
+    """
+    Run a specific list of argument filters on a command session.
+
+    This will call all argument filter functions successively,
+    with `session.current_arg` as the argument.
+
+    If all filters are passed, the final result will be put into
+    `session.state` with the key `session.current_key`.
+
+    If some validation failed, the session will be paused and
+    failure message will be sent to the user.
+
+    :param session: command session to run on
+    :param arg_filters: argument filters
+    """
     arg = session.current_arg
     for f in arg_filters:
         try: