html_url,issue_url,id,node_id,user,created_at,updated_at,author_association,body,reactions,performed_via_github_app,issue
https://github.com/pydata/xarray/issues/3890#issuecomment-605704846,https://api.github.com/repos/pydata/xarray/issues/3890,605704846,MDEyOklzc3VlQ29tbWVudDYwNTcwNDg0Ng==,10194086,2020-03-29T21:30:38Z,2020-03-29T21:30:38Z,MEMBER,"Not very elegant...

```python
from collections import Counter

input_core_dims = [[""time""], [""time"", ""foo""], [""bar""]]
exclude_dims = set([""time""])


c = Counter()
for dims in input_core_dims: 
    for d in dims: 
        if d in exclude_dims: 
            d_new = f""{d}_{c[d]}"" 
            c.update([d]) 
        else: 
            d_new = d 
        print(d_new)
```
","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,587735698
https://github.com/pydata/xarray/issues/3890#issuecomment-603882831,https://api.github.com/repos/pydata/xarray/issues/3890,603882831,MDEyOklzc3VlQ29tbWVudDYwMzg4MjgzMQ==,10194086,2020-03-25T14:49:08Z,2020-03-25T15:18:29Z,MEMBER,"In `apply_ufunc` the `signature` is determined in

https://github.com/pydata/xarray/blob/009aa66620b3437cf0de675013fa7d1ff231963c/xarray/core/computation.py#L995

and

https://github.com/pydata/xarray/blob/009aa66620b3437cf0de675013fa7d1ff231963c/xarray/core/computation.py#L1013-L1015

Thus, for the given example:
```python
signature = xr.core.computation._UFuncSignature(input_core_dims=[[""time""], [""time""]])
signature.to_gufunc_string()
```
returns `'(dim0),(dim0)->()'`.

So I assume `_UFuncSignature` (or `_UFuncSignature.to_gufunc_string`)  should take the `exclude_dims` into account.
","{""total_count"": 1, ""+1"": 1, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,587735698