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
514077742,MDU6SXNzdWU1MTQwNzc3NDI=,3458,Keep index dimension when selecting only a single coord,13770365,open,0,,,6,2019-10-29T17:02:29Z,2021-03-02T06:48:08Z,,NONE,,,,"#### MCVE Code Sample
<!-- In order for the maintainers to efficiently understand and prioritize issues, we ask you post a ""Minimal, Complete and Verifiable Example"" (MCVE): http://matthewrocklin.com/blog/work/2018/02/28/minimal-bug-reports -->

```python
# Your code here
import numpy as np
import xarray as xr

data = np.zeros((10, 4))
example_xr = xr.DataArray(data, coords=[range(10), [""idx0"", ""idx1"", ""idx2"", ""dim3""]], dims=[""rows"", ""cols""])

# desired behavior
subset = example_xr[:, 1:2]
subset.shape

# inclusive indexing means both idx1 and idx2 kept
subset_named1 = example_xr.loc[:, ""idx1"":""idx2""]
subset_named1.shape

# slicing behavior means that 2nd dimension is dropped
subset_named2 = example_xr.loc[:, ""idx1""]
subset_named2.shape
```

#### Expected Output
I'd like to be able to use named .loc indexing to select only a single named coord from one dimension, but not have that dimension collapse when subsetting. 

#### Problem Description
<!-- this should explain why the current behavior is a problem and why the expected output is a better solution -->

I looked, but wasn't able to find anything in the documentation about how to perform this same action using named coords. It works with integer-based slicing. 

#### Output of ``xr.show_versions()``
<details>
# Paste the output here xr.show_versions() here

</details>
","{""url"": ""https://api.github.com/repos/pydata/xarray/issues/3458/reactions"", ""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,,13221727,issue
568705055,MDU6SXNzdWU1Njg3MDUwNTU=,3785,open_dataarray(cache=False) still uses cached version of dataarray,13770365,closed,0,,,2,2020-02-21T02:58:22Z,2020-03-03T18:29:46Z,2020-03-03T18:29:46Z,NONE,,,,"#### MCVE Code Sample
<!-- In order for the maintainers to efficiently understand and prioritize issues, we ask you post a ""Minimal, Complete and Verifiable Example"" (MCVE): http://matthewrocklin.com/blog/work/2018/02/28/minimal-bug-reports -->

```python
# Your code here
import xarray as xr
import numpy as np
import os

# create two different xarrays with different sizes and coords
test_xr1 = xr.DataArray(np.zeros((5, 5, 3)), coords=[range(5), range(5), [""x1"", ""y1"", ""z1""]], dims=[""1"", ""2"", ""3""])
test_xr2 = xr.DataArray(np.zeros((10, 2, 3)), coords=[range(10), range(2), [""x2"", ""y2"", ""z2""]], dims=[""1"", ""2"", ""3""])

# save first xarray, reload it, and inspect coords
test_xr1.to_netcdf(""test_xr.xr"")
loaded_xr = xr.open_dataarray(""test_xr.xr"", cache=False)
loaded_xr.coords

Out[13]: 
Coordinates:
  * 1        (1) int64 0 1 2 3 4
  * 2        (2) int64 0 1 2 3 4
  * 3        (3) object 'x1' 'y1' 'z1'

# remove first xarray, save second with the same name, and load it
os.remove(""test_xr.xr"")
test_xr2.to_netcdf(""test_xr.xr"")
loaded_xr = xr.open_dataarray(""test_xr.xr"", cache=False)
loaded_xr.coords

Out[17]: 
Coordinates:
  * 1        (1) int64 0 1 2 3 4
  * 2        (2) int64 0 1 2 3 4
  * 3        (3) object 'x1' 'y1' 'z1'
```

#### Expected Output
Rather than loading the newly created/updated version of the file on disk, the cached version is used

#### Problem Description
<!-- this should explain why the current behavior is a problem and why the expected output is a better solution -->
If a file ever gets updated on disk and needs to be reloaded, this causes very mysterious bugs. Furthermore, the only workaround I found is to restart the python session. 

#### Output of ``xr.show_versions()``
<details>
# Paste the output here xr.show_versions() here
INSTALLED VERSIONS
------------------
commit: None
python: 3.6.5 |Anaconda, Inc.| (default, Apr 26 2018, 08:42:37) 
[GCC 4.2.1 Compatible Clang 4.0.1 (tags/RELEASE_401/final)]
python-bits: 64
OS: Darwin
OS-release: 18.7.0
machine: x86_64
processor: i386
byteorder: little
LC_ALL: None
LANG: None
LOCALE: en_US.UTF-8
libhdf5: 1.10.2
libnetcdf: 4.6.3
xarray: 0.12.1
pandas: 0.24.2
numpy: 1.16.3
scipy: 1.2.1
netCDF4: 1.5.3
pydap: None
h5netcdf: None
h5py: 2.10.0
Nio: None
zarr: None
cftime: 1.0.4.2
nc_time_axis: None
PseudonetCDF: None
rasterio: None
cfgrib: None
iris: None
bottleneck: None
dask: None
distributed: None
matplotlib: 2.2.2
cartopy: None
seaborn: 0.9.0
setuptools: 39.0.1
pip: 9.0.3
conda: None
pytest: 5.3.2
IPython: 7.11.1
sphinx: None
</details>
","{""url"": ""https://api.github.com/repos/pydata/xarray/issues/3785/reactions"", ""total_count"": 1, ""+1"": 1, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,completed,13221727,issue