Trying to use Python API - first example code fails

[gmeader]

installed ola using these commands:
Ubuntu 20.04.1 LTS
Install ola with python 3 support:

$ sudo apt install git libcppunit-dev libcppunit-1.15-0 uuid-dev pkg-config libncurses5-dev libtool autoconf automake g++ libmicrohttpd-dev libmicrohttpd12 protobuf-compiler libprotobuf-lite17 python-protobuf libprotobuf-dev libprotoc-dev zlib1g-dev bison flex make libftdi-dev libftdi1 libusb-1.0-0-dev liblo-dev libavahi-client-dev python-numpy
$ git clone https://github.com/OpenLightingProject/ola
$ cd ola
$ autoreconf -i
$ PYTHON=python3 ./configure --disable-unittests --disable-examples --disable-osc --enable-http --enable-python-libs
$ make
$ sudo make install
$ sudo ldconfig
]
==== seems ok
started olad - OK

I installed Python bindings for OLA, available as a package:
pip install ola
It installed v0.10.7

Ran the "A simple example to send one frame of DMX data" example code from https://www.openlighting.org/ola/developer-documentation/python-api/
Got the following error message:

/usr/bin/python3.9 /home/glenn/projects/ola/main.py
Traceback (most recent call last):
File "/home/glenn/projects/ola/main.py", line 11, in
client.SendDmx(universe, data, DmxSent)
File "/usr/local/lib/python3.9/dist-packages/ola/OlaClient.py", line 882, in SendDmx
request.data = data.tostring()
AttributeError: 'array.array' object has no attribute 'tostring'

Process finished with exit code 1

Running the Sending Multiple Frames example gives this error:
/usr/bin/python3.9 /home/glenn/projects/ola/main.py
Traceback (most recent call last):
File "/home/glenn/projects/ola/main.py", line 28, in
wrapper.Run()
File "/usr/local/lib/python3.9/dist-packages/ola/ClientWrapper.py", line 278, in Run
self._ss.Run()
File "/usr/local/lib/python3.9/dist-packages/ola/ClientWrapper.py", line 197, in Run
self._CheckTimeouts(now)
File "/usr/local/lib/python3.9/dist-packages/ola/ClientWrapper.py", line 222, in _CheckTimeouts
event.Run()
File "/usr/local/lib/python3.9/dist-packages/ola/ClientWrapper.py", line 67, in Run
self._callback()
File "/home/glenn/projects/ola/main.py", line 15, in SendDMXFrame
wrapper.AddEvent(TICK_INTERVAL, SendDMXFrame)
File "/usr/local/lib/python3.9/dist-packages/ola/ClientWrapper.py", line 287, in AddEvent
self._ss.AddEvent(time_in_ms, callback)
File "/usr/local/lib/python3.9/dist-packages/ola/ClientWrapper.py", line 215, in AddEvent
heapq.heappush(self._events, event)
TypeError: '<' not supported between instances of '_Event' and '_Event'

Process finished with exit code 1

[peternewman]

Hi @gmeader ,

Those are various issues we'd fixed in 0.10.8 or git for Python 3 compatibility.

Can you remove the pip version of OLA (unfortunately 20.04 is missing all our packaged versions) and then just use the version that the OLA make compiles/installs and that should work fine.

I'll talk to the person that built that pip package and try and get it a bit more under control...

[peternewman]

In terms of integrating the pip stuff, something like this could auto-release to pip for us!
codespell-project/codespell#2523

[hachpai]

Hello!
I just success to install olad 0.10.8, then pip install ola, and make everything working by git cloning the repo and copy the content of python/ola in .local/lib/python3.9/site-packages/ola.
Dirty but i can register universes, get new data...

pip install ola
git clone https://github.com/OpenLightingProject/ola.git
cp ola/python/ola/* /home/pi/.local/lib/python3.9/site-packages/ola

[peternewman]

Hi @hachpai ,

What's the benefit of that over just installing the OLA python stuff via configure/make?

Also just as a warning that will be rather brittle if we fix things in Protobuf or the RDM stuff, running make builtfiles first would cover the first bit, the second bit would involve a bit of both and grabbing files from ola/tools/rdm too (but it will need to be copied into ola/testing/rdm).