Categorical/enum datatypes cannot be parsed in polars

[mjclarke94]

Describe the bug

Nu cannot collect polars dataframes which have categorical datatypes.

How to reproduce

1. Use polars to write a simple parquet file with a categorical data type

import polars as pl

pl.DataFrame({"foo": ['a', 'b']}, schema_overrides={'foo': pl.Categorical}).write_parquet('example.parquet')

2. Attempt to read file

❯ polars open example.parquet | polars collect
Error:
  × Error creating Dataframe
  help: Value not supported in nushell: cat

3. Show file is valid by casting to string

❯ polars open example.parquet | polars cast str foo | polars collect
╭───┬─────╮
│ # │ foo │
├───┼─────┤
│ 0 │ a   │
│ 1 │ b   │
╰───┴─────╯

Expected behavior

Nu dataframes should be able to handle categorical data types and other types that are part of the parquet standard/native polars data types.

Configuration

key	value
version	0.101.0
major	0
minor	101
patch	0
branch
commit_hash
build_os	macos-aarch64
build_target	aarch64-apple-darwin
rust_version	rustc 1.83.0 (90b35a623 2024-11-26) (Homebrew)
cargo_version	cargo 1.83.0
build_time	2024-12-22 14:10:19 +00:00
build_rust_channel	release
allocator	mimalloc
features	default, sqlite, trash
installed_plugins	polars 0.101.0

[fdncred]

@ayax79 when you get a minute, it would be good to get your take on this.

[ayax79]

It looks like I will need to add the "dtype-categorical" feature to polars and add nushell conversion. I'll try to get to this this week.

[ayax79]

Fixed via #15292

I will provide the ability write categorical and enum data later.