altair 4.2 AttributeError: 'list' object has no attribute 'get' on chart.projection with center

[Casyfill]

with 4.2 Altair fails once I try to pass projection with center as a list:

>>> import altair as alt
>>> basic_chart = alt.Chart().properties(height=800, width=700)
>>> NYC_PRJ = {"type": "mercator", "center": [-73.99, 40.72]}
>>> basic_chart.project(**NYC_PRJ)

Raises this:

... /site-packages/jsonschema/validators.py", line 101, in _id_of
  return schema.get("$id", "")
AttributeError: 'list' object has no attribute 'get'

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[jakevdp]

Hi, thanks for the report - this looks quite similar to #2496

Which version of the jsonschema package do you have installed?

[Casyfill]

4.17.0, I assume I have to set it to <4

[Casyfill]

PS. confirming that jsonschema<4 fixes the issue

[joelostblom]

In addition to #2496, there is another issue with jsonschema 4.17 that is being tracked in #2705 so closing this issue for now but please comment if you think there is something that is not covered by those two issues.

[Casyfill]

Sure, thanks! is fixing altair to dfschema<4 as a temp patch an option?

[joelostblom]

Yeah we might do that (at least temporarily for CI) , but it wouldn't go into effect until the next release anyways so we should also try to figure out what goes wrong and make Altair compatible with newer json schema versions. Doing it locally with 4.2 would be totally ok.

[lennox55555]

How would you go about installing version <4 through !pip command