Can't get python interface to work

[kevinsung]

After following the instructions for setting up Python, I try to run the example script by executing python qflex_cirq_example.py. I get

Traceback (most recent call last):
  File "qflex_cirq_example.py", line 2, in <module>
    import python.cirq_interface.qflex_simulator as qsim
  File "/usr/local/google/home/sungkevin/Projects/qflex/python/cirq_interface/qflex_simulator.py", line 5, in <module>
    from python import qflex
ImportError: cannot import name 'qflex' from 'python' (unknown location)

[s-mandra]

Thanks for catching this. I've created a patch to solve the problem in #221. The problem is related to the fact that it's missing the relative path to where to find the qflex python modules. Try now with:

python3 python/qflex_cirq_example.py

from the root folder of qflex (it works for me).

[alexandrupaler]

Thank you for pointing this out. It is indeed an issue with the paths. However, we have also a relative paths related issue #167 . I guess the solution should consider module __init__.py.

[kevinsung]

It still doesn't work for me (same error).

[alexandrupaler]

Have you compiled QFlex with make pybind? In the pythonfolder there should be a file with a name like qflex.[long_name].so

[95-martin-orion]

Have you compiled QFlex with make pybind?

Note that this normally runs during the default make invocation; if it didn't, the logs should indicate what prevented it from doing so (usually missing dependencies, IIRC).

[kevinsung]

I didn't have pybind. Installing it fixed the issue. Thanks!

[alexandrupaler]

@s-mandra Should we suggest the user to run pip install -r requirements.txt if one if the python dependencies fail on configure?

[s-mandra]

Sure, I can add that to README.md and docs/install.md.