'lat' key not found when no metadata is given

[vergauwenthomas]

Multiple methods rely on the 'lat' and 'lon' column. Like in the __repr__of the dataset:

 if ((not self.metadf['lat'].isnull().all()) &
            (not self.metadf['lon'].isnull().all())):
            add_info += '    *Coordinates are available for all stations. \n'

So make sure these columns are always in the metadf attribute but filled with Nan if data is unknown.

Traceback (most recent call last):

File ~/anaconda3/envs/metobs_dev/lib/python3.9/site-packages/pandas/core/indexes/base.py:3790 in get_loc
return self._engine.get_loc(casted_key)

File index.pyx:152 in pandas._libs.index.IndexEngine.get_loc

File index.pyx:181 in pandas._libs.index.IndexEngine.get_loc

File pandas/_libs/hashtable_class_helper.pxi:7080 in pandas._libs.hashtable.PyObjectHashTable.get_item

File pandas/_libs/hashtable_class_helper.pxi:7088 in pandas._libs.hashtable.PyObjectHashTable.get_item

KeyError: 'lat'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):

File ~/anaconda3/envs/metobs_dev/lib/python3.9/site-packages/spyder_kernels/py3compat.py:356 in compat_exec
exec(code, globals, locals)

File ~/Documents/VLINDER_github/MetObs_toolkit/development/developscript.py:50
dataset.show()

File ~/Documents/VLINDER_github/MetObs_toolkit/metobs_toolkit/dataset.py:303 in show
print_dataset_info(self, show_all_settings)

File ~/Documents/VLINDER_github/MetObs_toolkit/metobs_toolkit/printing.py:30 in print_dataset_info
print(dataset)

File ~/Documents/VLINDER_github/MetObs_toolkit/metobs_toolkit/dataset.py:152 in str
if ((not self.metadf['lat'].isnull().all()) &

File ~/anaconda3/envs/metobs_dev/lib/python3.9/site-packages/pandas/core/frame.py:3896 in getitem
indexer = self.columns.get_loc(key)

File ~/anaconda3/envs/metobs_dev/lib/python3.9/site-packages/pandas/core/indexes/base.py:3797 in get_loc
raise KeyError(key) from err

KeyError: 'lat'