potential recursive import of 'quat'

[patzm]

I freshly installed scikit-kinematics, version 0.6.3, with pip3 into a Python 3.4.3 installation on Ubuntu 14.04 x64 LTS. When I try to import skinematics or any module included, I get the following:

Traceback (most recent call last):
  File "<input>", line 1, in <module>
  File "/usr/local/lib/python3.4/dist-packages/skinematics/__init__.py", line 29, in <module>
    importlib.import_module('.'+_m, package='skinematics')
  File "/usr/lib/python3.4/importlib/__init__.py", line 109, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "/usr/local/lib/python3.4/dist-packages/skinematics/imus.py", line 31, in <module>
    from skinematics import quat, vector, misc, rotmat
  File "/usr/local/lib/python3.4/dist-packages/skinematics/quat.py", line 28, in <module>
    from skinematics import vector, rotmat
  File "/usr/local/lib/python3.4/dist-packages/skinematics/vector.py", line 24, in <module>
    from skinematics import quat
ImportError: cannot import name 'quat'

I think this is due to the fact that vector.py imports the quat module as well, which in turn is imported when the module is loaded.

[thomas-haslwanter]

If two modules depend on each other, I don't see any other way. Also, if the module already exists in the current workspace, a new "import" should get ignored, unless it is forced. On my Linux mint 18.1 system, I just uninstalled any previous versions, and re-installed scikit-kinematics. I was not able to reproduce your problem (the fact that I am running Python 3.6 should make no difference here). Could you please update to 0.6.5, re-start the system, and try again? Thanks, th

[patzm]

I updated scikit-kinematics first to the most recent version 0.6.9 and then also tried with 0.6.5 as suggested. In both cases the error persisted. Here I provide a list of other installed packages. I hope that helps.

Furthermore I tried installing scikit-kinematics on a Ubuntu 17.10 x64 installation, which installs python 3.6.3 by default. Here it worked without problems.

Then I installed local environment with python 3.6.4 on the system that runs Ubuntu 14.04 LTS. Also in this local environment it worked... Did other users report issues with python 3.4 specifically?

[thomas-haslwanter]

Hmm, I do remember that I did have some similar problems on an earlier version of Python. But I did not take any notes (and don't remember) which versions those were. Is there a specific reason why you don't upgrade to Python 3.6.x? If it is a bigger problem for you, I will try to re-install an earlier version, and see if I can work around those installation specific problems. (Currently I don't have automated my tests, so that they automatically run for different versions of Python).

[patzm]

Thanks for you offer but it is not an impediment atm. I did manually install python 3.6 in the end. I guess the default one that ships with Ubuntu 14.04 is python 3.4. That might be the only argument why to fix it. After all, a lot of docker images for deep learning are based off this distribution and I guess some people from this field use also the kinematics toolbox from scikit.

[thomas-haslwanter]

Since there has been no new comment for more than a year, I close that issue.