set operations do not work with pl.lit, only with dataframe columns

[moritzwilksch]

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• I have confirmed this bug exists on the latest version of Polars.

Issue description

The newly added set operations seem to have problems with using pl.lit(). They only work as expected on other dataframe columns.

Reproducible example

import polars as pl

df = pl.DataFrame({"a": [[1, 2, 3], [4, 5]]})

df.with_columns(b=pl.lit([[3, 4, 6]])).select(pl.col("a").list.intersection("b"))
# shape: (2, 1)
# ┌───────────┐
# │ a         │
# │ ---       │
# │ list[i64] │
# ╞═══════════╡
# │ [3]       │
# │ [4]       │
# └───────────┘

df.select(pl.col("a").list.intersection(pl.lit([[3, 4, 6]])))
# PanicException: assertion failed: `(left == right)`
#   left: `3`,
#  right: `2`

Expected behavior

The behavior should be identical between using a literal expression or an existing dataframe column.

Installed versions

--------Version info---------
Polars:              0.18.6
Index type:          UInt32
Platform:            Linux-5.4.0-1103-aws-x86_64-with-glibc2.31
Python:              3.10.12 | packaged by conda-forge | (main, Jun 23 2023, 22:40:32) [GCC 12.3.0]

----Optional dependencies----
adbc_driver_sqlite:  <not installed>
connectorx:          <not installed>
deltalake:           <not installed>
fsspec:              <not installed>
matplotlib:          3.7.1
numpy:               1.21.6
pandas:              1.5.3
pyarrow:             12.0.0
pydantic:            1.10.9
sqlalchemy:          1.4.48
xlsx2csv:            <not installed>
xlsxwriter:          <not installed>

[deanm0000]

This is intended, see here

[moritzwilksch]

Hmm fair, but then I would expect this to behave similarly to is_in which can also take literal lists as arguments, no?

df.select(pl.col("a").list.intersection([3, 4, 6]))
# PanicException: assertion failed: `(left == right)`
#  left: `3`,
#  right: `2`

[deanm0000]

I'm not following you.

[ritchie46]

No, the literal should broadcast in this case. As it is an argument to the set function. That's within our broadcasting rules.

[orlp]

This was solved in #10668.