{"database": "github", "table": "issues", "rows": [[189481649, "MDU6SXNzdWUxODk0ODE2NDk=", 1123, "Assigning several variables at once in a dataset", 6333189, "closed", 0, null, null, 3, "2016-11-15T19:20:44Z", "2021-05-02T20:29:34Z", "2021-05-02T20:29:34Z", "NONE", null, null, null, "Hi,\r\n\r\nI cannot tell if I'm doing something illegitimate. I have a hard time to understand the error I'm facing:\r\n\r\n```python\r\nimport numpy as np\r\nimport xarray as xr\r\n\r\nds = xr.Dataset(\r\n    {'varA': (['x', 'time'], np.random.rand(2, 2)),\r\n     'varB': (['x', 'time'], np.random.rand(2, 2)),\r\n     'varC': (['x', 'time'], np.random.rand(2, 2))},\r\n    coords={'x': [0, 1.], 'time': [0, 1.]})\r\n\r\nprint(ds)\r\n\r\n# I want to center 'varA' and 'varB' by substracting their mean values along the time dimension:\r\nds[['varA', 'varB']] -= ds[['varA', 'varB']].mean(dim='time')\r\n```\r\n\r\nProduces the output:\r\n```\r\n<xarray.Dataset>\r\nDimensions:  (time: 2, x: 2)\r\nCoordinates:\r\n  * x        (x) float64 0.0 1.0\r\n  * time     (time) float64 0.0 1.0\r\nData variables:\r\n    varA     (x, time) float64 0.7737 0.2608 0.009832 0.8498\r\n    varC     (x, time) float64 0.9732 0.6492 0.5118 0.5792\r\n    varB     (x, time) float64 0.04973 0.4012 0.01248 0.8716\r\n---------------------------------------------------------------------------\r\nTypeError                                 Traceback (most recent call last)\r\n<ipython-input-36-aa87123fb25d> in <module>()\r\n      7 print(ds)\r\n      8 \r\n----> 9 ds[['varA', 'varB']] -= ds[['varA', 'varB']].mean(dim='time')\r\n\r\nC:\\Users\\poimat04\\AppData\\Local\\Continuum\\Miniconda2\\envs\\AxialLLRCA\\lib\\site-packages\\xarray\\core\\dataset.pyc in __setitem__(self, key, value)\r\n    536             raise NotImplementedError('cannot yet use a dictionary as a key '\r\n    537                                       'to set Dataset values')\r\n--> 538         self.update({key: value})\r\n    539 \r\n    540     def __delitem__(self, key):\r\n\r\nTypeError: unhashable type: 'list'\r\n```\r\n\r\nIs it forbidden to assign several variables at once? I'm puzzled with this TypeError.\r\n\r\nThanks", "{\"url\": \"https://api.github.com/repos/pydata/xarray/issues/1123/reactions\", \"total_count\": 0, \"+1\": 0, \"-1\": 0, \"laugh\": 0, \"hooray\": 0, \"confused\": 0, \"heart\": 0, \"rocket\": 0, \"eyes\": 0}", null, "completed", 13221727, "issue"]], "columns": ["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"], "primary_keys": ["id"], "primary_key_values": ["189481649"], "units": {}, "query_ms": 2.7560240050661378}