id,node_id,number,title,user,state,locked,assignee,milestone,comments,created_at,updated_at,closed_at,author_association,active_lock_reason,draft,pull_request,body,reactions,performed_via_github_app,state_reason,repo,type
1422460071,I_kwDOAMm_X85UyQSn,7211,Incorrect handle to Dagster frozenlists in Dataset object,64480652,closed,0,,,4,2022-10-25T13:23:09Z,2022-10-31T12:39:05Z,2022-10-31T12:39:05Z,NONE,,,,"### What happened?

Dataset object could not be fetched with Dataset[variables] when variables is a frozenlist. There is some source code that can replicate this behaviour.

### What did you expect to happen?

Dataset[variables] returning a new fetched dataset. It returns a key error.

### Minimal Complete Verifiable Example

```Python
# %%
from dagster import Output, asset, Field, build_op_context
import numpy as np
import pandas as pd
import xarray as xr

def retrieve_dataset(date, fct_step, lats, lons, runtime, source, variables):

    dt = str(date)[0:10].replace(""-"", """")
    year = dt[0:4]
    prev_n = ""{}"".format(fct_step).zfill(3)

    lat_toplot = np.arange(
        min(lats), max(lats), 0.25
    )  # last number is exclusive
    lon_toplot = (
        np.arange(min(lons), max(lons), 0.25) % 360
    )  # last number is exclusive

    gfs_model = ""ds084.1""
    URL = f""https://rda.ucar.edu/thredds/dodsC/files/g/{gfs_model}/{year}/{dt}/gfs.0p25.{dt}{runtime}.f{prev_n}.grib2""

    dataset = xr.open_dataset(URL, cache=True, engine=""netcdf4"")[variables]

    # Select required data via xarray
    dataset = dataset.sel(lon=lon_toplot, lat=lat_toplot)[variables]

    return dataset


@asset(
    description=""GFS dataset fetched for NOAA Forecast data from NOAA NOMADS server."",
    config_schema=dict(
        variables=Field(list),
    ),
    output_required=True,
)
def ncar_dataset(context):

    date = ""2022-02-01""
    fct_step = 0
    lats = [-4.0, -2.75]
    lons = [-41.5, -40.25]
    runtime = ""00""
    # variables = list(context.op_config[""variables""])  <--- This way it runs
    variables = context.op_config[""variables""]
    source = ""model-gfs-003""

    dataset = retrieve_dataset(
        date, fct_step, lats, lons, runtime, source, variables
    )

    return Output(dataset)



test_variable = ""u-component_of_wind_height_above_ground""

with build_op_context(
    op_config={
        ""variables"": [test_variable],
    }
) as context:

    dataset_ast = ncar_dataset(context)
dataset = dataset_ast.value
```


### MVCE confirmation

- [X] Minimal example — the example is as focused as reasonably possible to demonstrate the underlying issue in xarray.
- [ ] Complete example — the example is self-contained, including all data and the text of any traceback.
- [X] Verifiable example — the example copy & pastes into an IPython prompt or [Binder notebook](https://mybinder.org/v2/gh/pydata/xarray/main?urlpath=lab/tree/doc/examples/blank_template.ipynb), returning the result.
- [X] New issue — a search of GitHub Issues suggests this is not a duplicate.

### Relevant log output

```Python
I raises KeyError
```


### Anything else we need to know?

_No response_

### Environment

<details>
Python 3.10.4

pandas==1.5.0
xarray==0.19.0
netCDF4==1.5.7
dagster
dagit
</details>
","{""url"": ""https://api.github.com/repos/pydata/xarray/issues/7211/reactions"", ""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,completed,13221727,issue