diff --git a/docs/python/faq.md b/docs/python/faq.md
index bf07639..4a6a4ae 100644
--- a/docs/python/faq.md
+++ b/docs/python/faq.md
@@ -279,4 +279,8 @@ A scope is a textual region of a Python program, where a namespace is directly a
 
 
 ???- question "How to program web socket server"
-    See [FastAPI doc](https://fastapi.tiangolo.com/advanced/websockets/) with [testing](https://fastapi.tiangolo.com/advanced/testing-websockets/) and matching code in [](https://github.com/jbcodeforce/python-code/tree/master/web-server/websocket_server)
\ No newline at end of file
+      See [FastAPI doc](https://fastapi.tiangolo.com/advanced/websockets/) with [testing](https://fastapi.tiangolo.com/advanced/testing-websockets/) and matching code in [websocket_server](https://github.com/jbcodeforce/python-code/tree/master/web_server/websocket_server)
+
+???- question "Using async IO?"
+      async IO is a single-threaded, single-process design: it uses cooperative multitasking. [See this tutorial](https://realpython.com/async-io-python/): concurrency encompasses both multiprocessing (ideal for CPU-bound tasks) and threading (suited for IO-bound tasks). Async io is supported by `async` and `await` language keywords. Asynchronous routines are able to “pause” while waiting on their ultimate result and let other routines run in the meantime.  `await` passes function control back to the event loop
+      See code in [api_stream](https://github.com/jbcodeforce/python-code/tree/master/web_server/api_stream/)
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diff --git a/docs/python/pydantic.md b/docs/python/pydantic.md
index cef6007..8a4e571 100644
--- a/docs/python/pydantic.md
+++ b/docs/python/pydantic.md
@@ -1,2 +1,4 @@
 # Pydantic
 
+[]()
+
diff --git a/web-server/Dockerfile b/web_server/Dockerfile
similarity index 100%
rename from web-server/Dockerfile
rename to web_server/Dockerfile
diff --git a/web_server/api_stream/client.py b/web_server/api_stream/client.py
new file mode 100644
index 0000000..82d8709
--- /dev/null
+++ b/web_server/api_stream/client.py
@@ -0,0 +1,6 @@
+import requests
+
+
+with requests.get("http://localhost:8000", stream=True) as r:
+    for chunk in r.iter_content(100):
+        print(chunk)
\ No newline at end of file
diff --git a/web_server/api_stream/server.py b/web_server/api_stream/server.py
new file mode 100644
index 0000000..cea1010
--- /dev/null
+++ b/web_server/api_stream/server.py
@@ -0,0 +1,21 @@
+from fastapi import FastAPI
+from typing import Generator
+from fastapi.responses import StreamingResponse
+
+app = FastAPI()
+
+# coroutine which will suspend the execution if there is await or yield
+# yield creates an asynchronous generator, which we iterate over with async for.
+async def fake_video_streamer():
+    for i in range(10):
+        yield b"some fake video bytes"
+
+# another example
+# A simple method to open the file and get the data
+async def get_data_from_file(file_path: str) -> Generator:
+    with open(file=file_path, mode="rb") as file_like:
+        yield file_like.read()
+
+@app.get("/")
+async def main():
+    return StreamingResponse(content=fake_video_streamer(),media_type="text/media")
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diff --git a/web_server/api_stream/start_server.sh b/web_server/api_stream/start_server.sh
new file mode 100644
index 0000000..573977f
--- /dev/null
+++ b/web_server/api_stream/start_server.sh
@@ -0,0 +1 @@
+uvicorn server:app --port 8000
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diff --git a/web-server/fastapi_main.py b/web_server/fastapi_main.py
similarity index 100%
rename from web-server/fastapi_main.py
rename to web_server/fastapi_main.py
diff --git a/web-server/requirements.txt b/web_server/requirements.txt
similarity index 100%
rename from web-server/requirements.txt
rename to web_server/requirements.txt
diff --git a/web-server/websocket_server/TestWSServer.py b/web_server/websocket_server/TestWSServer.py
similarity index 100%
rename from web-server/websocket_server/TestWSServer.py
rename to web_server/websocket_server/TestWSServer.py
diff --git a/web-server/websocket_server/a_client.py b/web_server/websocket_server/a_client.py
similarity index 100%
rename from web-server/websocket_server/a_client.py
rename to web_server/websocket_server/a_client.py
diff --git a/web-server/websocket_server/main.py b/web_server/websocket_server/main.py
similarity index 100%
rename from web-server/websocket_server/main.py
rename to web_server/websocket_server/main.py