Coerce pd.Series to dicts in Metadata.custom. Closes #232.

onecodex/models/sample.py

@@ -1,3 +1,4 @@
+import json
 from requests.exceptions import HTTPError
 from six import string_types
 import warnings
@@ -184,6 +185,19 @@ def __hash__(self):
 class Metadata(OneCodexBase):
     _resource_path = '/api/v1/metadata'
 
+    def __setattr__(self, key, value):
+        # At some point we should validate that these match the schema
+        if key == 'custom':
+            try:
+                import pandas as pd
+
+                if isinstance(value, pd.Series):
+                    value = json.loads(value.to_json())
+            except ImportError:
+                pass
+
+        super(Metadata, self).__setattr__(key, value)
+
     def save(self):
         if self.id is None:
             super(Metadata, self).save()  # Create