Add native AsyncClient with asyncio support

README.rst

@@ -68,3 +68,20 @@ Install using pip::
    $ pip install python-snap7
 
 No native libraries or platform-specific dependencies are required — python-snap7 is a pure Python package that works on all platforms.
+
+
+Async support
+=============
+
+An ``AsyncClient`` is available for use with ``asyncio``::
+
+   import asyncio
+   import snap7
+
+   async def main():
+       async with snap7.AsyncClient() as client:
+           await client.connect("192.168.1.10", 0, 1)
+           data = await client.db_read(1, 0, 4)
+           print(data)
+
+   asyncio.run(main())

doc/API/async_client.rst

@@ -0,0 +1,43 @@
+AsyncClient
+===========
+
+The :class:`~snap7.async_client.AsyncClient` provides a native ``asyncio``
+interface for communicating with Siemens S7 PLCs.  It has feature parity with
+the synchronous :class:`~snap7.client.Client` and is safe for concurrent use
+via ``asyncio.gather()``.
+
+Quick start
+-----------
+
+.. code-block:: python
+
+   import asyncio
+   import snap7
+
+   async def main():
+       async with snap7.AsyncClient() as client:
+           await client.connect("192.168.1.10", 0, 1)
+           data = await client.db_read(1, 0, 4)
+           print(data)
+
+   asyncio.run(main())
+
+Concurrent reads
+----------------
+
+An internal ``asyncio.Lock`` serialises each send/receive cycle so that
+multiple coroutines can safely share a single connection:
+
+.. code-block:: python
+
+   results = await asyncio.gather(
+       client.db_read(1, 0, 4),
+       client.db_read(1, 10, 4),
+   )
+
+API reference
+-------------
+
+.. automodule:: snap7.async_client
+   :members:
+   :exclude-members: AsyncISOTCPConnection

doc/index.rst

@@ -11,6 +11,7 @@ Contents:
    development
 
    API/client
+   API/async_client
    API/server
    API/partner
    API/logo

pyproject.toml

@@ -32,7 +32,7 @@ Homepage = "https://github.com/gijzelaerr/python-snap7"
 Documentation = "https://python-snap7.readthedocs.io/en/latest/"
 
 [project.optional-dependencies]
-test = ["pytest", "pytest-cov", "pytest-html", "mypy", "types-setuptools", "ruff", "tox", "tox-uv", "types-click", "uv"]
+test = ["pytest", "pytest-asyncio", "pytest-cov", "pytest-html", "mypy", "types-setuptools", "ruff", "tox", "tox-uv", "types-click", "uv"]
 cli = ["rich", "click" ]
 doc = ["sphinx", "sphinx_rtd_theme"]
 

snap7/__init__.py

@@ -8,6 +8,7 @@
 from importlib.metadata import version, PackageNotFoundError
 
 from .client import Client
+from .async_client import AsyncClient
 from .server import Server
 from .partner import Partner
 from .logo import Logo
@@ -16,6 +17,7 @@
 
 __all__ = [
     "Client",
+    "AsyncClient",
     "Server",
     "Partner",
     "Logo",