Merge pull request #24 from pysat/meta_fix

BUG: netCDF4 file compatibility

CHANGELOG.md

@@ -4,6 +4,9 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [0.?.?] - 2020-07-03
 - Added coords from pysat.utils
+- Bug Fix
+   - Updated madrigal methods to simplify compound data types and enable
+     creation of netCDF4 files using `Instrument.to_netcdf4()`.
 
 ## [0.0.3] - 2020-06-15
 - pypi compatibility

pysatMadrigal/instruments/methods/madrigal.py

@@ -89,10 +89,7 @@ def load(fnames, tag=None, inst_id=None, xarray_coords=[]):
     file_meta = filed['Metadata']['Data Parameters']
     # load up what is offered into pysat.Meta
     meta = pysat.Meta()
-    meta.info = {'acknowledgements':
-                 ' '.join(["See 'meta.Experiment_Notes' for instrument",
-                           "specific acknowledgements\n", cedar_rules()]),
-                 'references': "See 'meta.Experiment_Notes' for references"}
+
     labels = []
     for item in file_meta:
         # handle difference in string output between python 2 and 3
@@ -115,6 +112,18 @@ def load(fnames, tag=None, inst_id=None, xarray_coords=[]):
     for key in filed['Metadata']:
         if key != 'Data Parameters':
             setattr(meta, key.replace(' ', '_'), filed['Metadata'][key][:])
+
+    # Update formatting of madrigal experiment information since
+    # netcdf4 doesn't recommend compound data types.
+    mad_vars = [('Experiment_Parameters', ': '),
+                ('Independent_Spatial_Parameters', ': '),
+                ('Experiment_Notes', '')]
+    for mad_var in mad_vars:
+        snips = [[snip.decode('UTF-8') for snip in items] for items in
+                 getattr(meta, mad_var[0])]
+        snips = [mad_var[1].join(snip) for snip in snips]
+        setattr(meta, mad_var[0], snips)
+
     # data into frame, with labels from metadata
     data = pds.DataFrame.from_records(file_data, columns=labels)
     # lowercase variable names