Fix partial autorange when range contains None elements

[Krishnachaitanyakc]

Summary

Fixes #5536

When setting range=[value, None] or range=[None, value] on an axis (e.g., fig.update_yaxes(range=[0, None])), plotly.js should use partial autoranging to fix one bound while autoranging the other. However, the plotly.js impliedEdits mechanism automatically sets autorange=false whenever range is specified, which prevents partial autoranging from working.

This PR fixes the issue by explicitly setting the autorange property to the appropriate value when range contains None elements:

• range=[value, None] sets autorange="max" (fix lower bound, autorange upper)
• range=[None, value] sets autorange="min" (autorange lower, fix upper bound)
• range=[None, None] sets autorange=True (autorange both)
• range=[value, value] does not set autorange (no change, existing behavior)

The fix is implemented in two places in plotly/basedatatypes.py:

1. _perform_update -- handles update_yaxes(), update_xaxes(), update_layout(), and other update methods. When autorange is explicitly provided by the user in the same update call, the explicit value takes precedence.
2. __setitem__ -- handles direct property assignment like fig.layout.yaxis.range = [0, None].

Test plan

• Added 9 unit tests in tests/test_core/test_update_objects/test_update_subplots.py covering:
  • Upper bound None sets autorange="max"
  • Lower bound None sets autorange="min"
  • Both bounds None sets autorange=True
  • No None does not set autorange
  • Works on both xaxis and yaxis
  • Explicit autorange in same update call takes precedence
  • Dict ordering does not affect explicit autorange precedence
  • Direct property assignment works
  • update_layout(yaxis_range=...) works
• All existing tests pass (1735 passed, 1 pre-existing failure unrelated to this change)

[camdecoster]

Thanks for the PR. One of our team members will review and follow up.

[emilykl]

Hi @Krishnachaitanyakc, thanks for the contribution.

I'm not totally sure this addresses the root issue, since I can see that in plotly.py 6.6.0, autorange is already correctly set to "max" in plotly.js when only a lower bound is provided in plotly.py:

That said, it's at least plausible that we might want to do special handling of autorange in plotly.py.

Could you update your PR description to match the template and include screenshots/videos of the fix in action?

Take a look at my comment here as well which has a tiny bit more info.