PR to fix bugs to python-opcua are welcome, but if you want to write new fancy features or architectural changes, please look at opcua-asyncio
Why asyncio? because it makes code easier to read and safer(read: less chances for bugs) and since python is monoprocess it might even be faster. It is also a good timing to remove all Python2 code
OPC UA binary protocol implementation is quasi complete and has been tested against many different OPC UA stacks. API offers both a low level interface to send and receive all UA defined structures and high level classes allowing to write a server or a client in a few lines. It is easy to mix high level objects and low level UA calls in one application.
Most low level code is autogenerated from xml specification, thus adding missing functionality to client or server is often trivial.
coverage.py reports a test coverage of over 95 % of code, most of non-tested code is autogenerated code that is not used yet.
With pip (note: the package was ealier called freeopcua)
pip install opcua
apt install python-opcua # Library apt install python-opcua-tools # Command-line tools
concurrent.futures), with pip for example.
Some documentation is available on ReadTheDocs.
A simple GUI client is available: https://github.com/FreeOpcUa/opcua-client-gui
Minimal client example: https://github.com/FreeOpcUa/python-opcua/blob/master/examples/client-minimal.py Minimal server example: https://github.com/FreeOpcUa/python-opcua/blob/master/examples/server-minimal.py
A set of command line tools also available: https://github.com/FreeOpcUa/python-opcua/tree/master/tools
uadiscover(find_servers, get_endpoints and find_servers_on_network calls)
uals(list children of a node)
uaread(read attribute of a node)
uawrite(write attribute of a node)
uacall(call method of a node)
uasubscribe(subscribe to a node and print datachange events)
uaclient(connect to server and start python shell)
uaserver(starts a demo OPC UA server)
tools/uaserver --populate --certificate cert.pem --private_key pk.pem
How to generate certificate: https://github.com/FreeOpcUa/python-opcua/tree/master/examples/generate_certificate.sh
Tested servers: freeopcua C++, freeopcua Python, prosys, kepware, beckhoff, winCC, B&R, …
Not implemented yet:
Tested clients: freeopcua C++, freeopcua Python, uaexpert, prosys, quickopc
Not yet implemented:
Setting up the standard address-space from XML is the most time-consuming step of the startup process which may lead to long startup times on less powerful devices like a Raspberry Pi. By passing a path to a cache-file to the server constructor, a shelve holding the address space will be created during the first startup. All following startups will make use of the cache-file which leads to significantly better startup performance (~3.5 vs 125 seconds on a Raspberry Pi Model B).
Code follows PEP8 apart for line lengths which should be max 120 characters and OPC UA structures that keep camel case from XML definition.
All protocol code is under opcua directory
opcua/uacontains all UA structures from specification, most are autogenerated
opcua/commoncontains high level objects and methods used both in server and client
opcua/clientcontains client specific code
opcua/servercontains server specific code
opcua/utilscontains some utilities function and classes
opcua/toolscontains code for command lines tools
schemascontains the XML and text files from specification and the python scripts used to autogenerate code
docscontains files to auto generate documentation from doc strings
examplescontains many example files
toolscontains python scripts that can be used to run command line tools from repository without installing
coverage run tests.py coverage html firefox htmlcov/index.html