Confusing error message for invalid key

If the API key (by accident) is set to an invalid value:

$ cat .cdsapirc
url: https://cds.climate.copernicus.eu/api/v2
key: dummy

and we run the test example:

>>> import cdsapi
>>> cds = cdsapi.Client()
>>> cds.retrieve('reanalysis-era5-pressure-levels', {
           "variable": "temperature",
           "pressure_level": "1000",
           "product_type": "reanalysis",
           "date": "2017-12-01/2017-12-31",
           "time": "12:00",
           "format": "grib"
       }, 'download.grib')

we get an error message which is not very informative:

2019-05-15 08:54:26,421 INFO Sending request to https://cds.climate.copernicus.eu/api/v2/resources/reanalysis-era5-pressure-levels
Traceback (most recent call last):
  File "<stdin>", line 8, in <module>
  File "/home/jbl/.local/lib/python3.6/site-packages/cdsapi/api.py", line 230, in retrieve
    result = self._api('%s/resources/%s' % (self.url, name), request)
  File "/home/jbl/.local/lib/python3.6/site-packages/cdsapi/api.py", line 245, in _api
    result = self.robust(session.post)(url, json=request, verify=self.verify)
  File "/home/jbl/.local/lib/python3.6/site-packages/cdsapi/api.py", line 362, in wrapped
    r = call(*args, **kwargs)
  File "/home/jbl/.local/lib/python3.6/site-packages/requests/sessions.py", line 581, in post
    return self.request('POST', url, data=data, json=json, **kwargs)
  File "/home/jbl/.local/lib/python3.6/site-packages/requests/sessions.py", line 519, in request
    prep = self.prepare_request(req)
  File "/home/jbl/.local/lib/python3.6/site-packages/requests/sessions.py", line 462, in prepare_request
    hooks=merge_hooks(request.hooks, self.hooks),
  File "/home/jbl/.local/lib/python3.6/site-packages/requests/models.py", line 317, in prepare
    self.prepare_auth(auth, url)
  File "/home/jbl/.local/lib/python3.6/site-packages/requests/models.py", line 548, in prepare_auth
    r = auth(self)
TypeError: 'tuple' object is not callable

[jeverling]

I think the error message comes because when you don’t provide <UID>:<API_KEY> but e.g. only <API_KEY>, you will end up with a tuple with only one element after the split(":") in https://github.com/ecmwf/cdsapi/blob/24f0a4e/cdsapi/api.py#L324

You can pass either a tuple with ("username", "password") to requests, or a callable. So requests sees this isn’t a tuple with len 2, and tries to call it. Hence the error message. I think it would be good to check whether the result of the split actually has 2 elements, and raise a more descriptive error when not.

[gmt3141]

I had same problem. After login to Copernicus website and accepting the license terms at following URL, my problem solved:

https://cds.climate.copernicus.eu/cdsapp/#!/terms/licence-to-use-copernicus-products