--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/asyncio_threads/stop_token/main.py	Sat Dec 13 14:23:02 2025 -0800
@@ -0,0 +1,42 @@
+from typing import Generator
+from typing import List
+
+# [Hello There, "I am <EN", "D> Something"]
+#     |
+
+def truncate_stream(text_stream: Generator[str, None, None], stop_token: str) -> Generator[str, None, None]:
+    buffer = ""
+    for chunk in text_stream:
+        can_be_prefix = False
+        buffer += chunk
+        if stop_token not in buffer:
+            for end in range(1, len(stop_token)):
+                if stop_token[:end] in buffer[-1 * len(stop_token):]:
+                    can_be_prefix = True
+            if not can_be_prefix:
+                yield chunk
+                buffer = ""
+        else: 
+            pos = buffer.find(stop_token)
+            yield buffer[:pos]
+            return
+
+def stream_to_list(stream: Generator[str, None, None]) -> List[str]:
+    return [chunk for chunk in stream]
+
+def list_to_stream(chunks: List[str]) -> Generator[str, None, None]:
+    for chunk in chunks:
+        yield chunk
+
+
+print(
+    stream_to_list(
+        truncate_stream(list_to_stream(["Hello there ", "I'm doing great today.<END>", "Thanks for asking.", "How are you"]), "<END>")
+    )
+) 
+
+print(
+    stream_to_list(
+        truncate_stream(list_to_stream(["Hello there ", "I'm doing great today.<E", "N", "D>", "Thanks for asking.", "How are you"]), "<END>")
+    )
+)