Add TensorflowCustomBackend class from qibo

[stavros11]

Following qiboteam/qibo#500 this adds the TensorflowCustomBackend that was previously in qibo here. Since this class inherits the AbstractBackend from qibo, qibo is now added in the requirements list for qibotf.

@scarrazza I tried removing the requirements.txt similarly to what you did for qibo and qibojit but there seems to be an issue here. Is there another reason this file is required here? If yes, I will put it back and just add the qibo requirement there.

[scarrazza]

@stavros11 thanks for this. Indeed, for this repository we need the requirements, given that tensorflow must be installed before running setup.py, and we use that file for the versioning control.

[codecov]

Codecov Report

Merging #12 (444a4b3) into main (4116d05) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##              main       #12    +/-   ##
==========================================
  Coverage   100.00%   100.00%            
==========================================
  Files            3         5     +2     
  Lines          371       528   +157     
==========================================
+ Hits           371       528   +157     

Flag	Coverage Δ
unittests	100.00% <100.00%> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
src/qibotf/custom_operators/__init__.py	100.00% <100.00%> (ø)
...m_operators/python/ops/qibo_tf_custom_operators.py	100.00% <100.00%> (ø)
src/qibotf/tests/conftest.py	100.00% <100.00%> (ø)
src/qibotf/tests/test_gates.py	100.00% <100.00%> (ø)
src/qibotf/tests/test_ops.py	100.00% <100.00%> (ø)

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[stavros11]

@scarrazza, following what we discussed I removed the qibo requirement for testing. I also had to remove qibo from the requirements.txt for this to work, which I assume is okay, given that qibotf is "useless" for external users without qibo. Now CI tests seem to pass, however there is an issue with the build. Is this because qibo is required to build the wheels?

[scarrazza]

@stavros11 thanks. No, I think this is related to auditwheels/py36.

[stavros11]

I added some tests for TensorflowCustomBackend to get the coverage back to 100%. Similarly to qiboteam/qibojit#35 here I am installing qibo from source until the new backend independent version is released. I also had to disable Python 3.6.

@scarrazza, do you have any idea why pylint is failing here?

[scarrazza]

@scarrazza, do you have any idea why pylint is failing here?

Should be the incompatibility you have fixed here: 024c165

[stavros11]

Should be the incompatibility you have fixed here: 024c165

I am giving this another try but I believe this results to some other installation issues.

[scarrazza]

I am giving this another try but I believe this results to some other installation issues.

@stavros11 just fixed now.

[stavros11]

@stavros11 just fixed now.

Thanks for the fix. This should be good to go, we just need to remember to reset the CI to pip install qibo --pre and re-enable Python 3.6 once qibo is released.

[scarrazza]

@stavros11 thanks, I am looking into py36 right now. The major issue we have is that some qibo dependency is asking for matplotlib 3.4 which is not compatible with py36, I am not sure which package is forcing that version, however if we can get rid or disable this requirement for qibo then we can retry this PR with an updated version of the backendcls branch.

[stavros11]

@stavros11 thanks, I am looking into py36 right now. The major issue we have is that some qibo dependency is asking for matplotlib 3.4 which is not compatible with py36, I am not sure which package is forcing that version, however if we can get rid or disable this requirement for qibo then we can retry this PR with an updated version of the backendcls branch.

I believe the py36 issue disappears if I install qibo using pip install . like you do here instead of python setup.py develop. I just pushed this in qiboteam/qibojit#35 and I think CI passes.

[scarrazza]

Ok, I will have another look, the problem was raised from https://github.com/qiboteam/qibotf/runs/4092821511?check_suite_focus=true#step:5:235.

On the other hand looks like keras-2.7.0 is breaking the actions for qibo https://github.com/qiboteam/qibo/actions/runs/1421436395. If pinning down to 2.6.0 works then we will have to include this requirement here.