avail_circ_modes set to None causes OpenPMDTimeSeries.slider() to fail

[openpmd]

avail_circ_modes set to None causes OpenPMDTimeSeries.slider() to fail

[RemiLehe]

Thanks a lot for pointing this out 😄 I think @ncook882 was observing the same bug during USPAS, but I forgot to follow up on this.

In any case, I think the solution that you propose (in params_reader.py L99) is great. Would you be willing to do a pull request with this change (see CONTRIBUTING.md), and put me as a reviewer? It may seem a little bit overkill to do a PR for just one line of code, but it allows us to nicely track issues and contributions to the code, so I would still go for it.

Thanks again!!

PS: Out of curiosity, which version of ipywidgets are you using? It seems that, depending on the version of this package, users may or may not observe this bug.

[jgerity]

Sure, I'll put in a PR with that change (and possibly moving L270-272 from interactive.py up into the check at L262 of the same, if you agree*), I wanted to open an issue first to make sure I hadn't misunderstood something about the way thetaMode works.

I'm using ipywidgets version 5.1.5.

edit:
Upon closer examination, those lines are referenced elsewhere, so it's probably better to leave them as they are, since the behavior is correct with an empty avail_circ_modes list anyway.

[RemiLehe]

Closed by PR #119