MAINT: Make error message for missing datatype more precise

src/caosadvancedtools/models/parser.py

@@ -316,19 +316,22 @@ class Parser(object):
                     self.model[name].description = prop
 
                 elif prop_name == "recommended_properties":
-                    self._add_to_recordtype(name, prop, importance=db.RECOMMENDED)
+                    self._add_to_recordtype(
+                        name, prop, importance=db.RECOMMENDED)
 
                     for n, e in prop.items():
                         self._treat_entity(n, e)
 
                 elif prop_name == "obligatory_properties":
-                    self._add_to_recordtype(name, prop, importance=db.OBLIGATORY)
+                    self._add_to_recordtype(
+                        name, prop, importance=db.OBLIGATORY)
 
                     for n, e in prop.items():
                         self._treat_entity(n, e)
 
                 elif prop_name == "suggested_properties":
-                    self._add_to_recordtype(name, prop, importance=db.SUGGESTED)
+                    self._add_to_recordtype(
+                        name, prop, importance=db.SUGGESTED)
 
                     for n, e in prop.items():
                         self._treat_entity(n, e)
@@ -355,9 +358,13 @@ class Parser(object):
         self.treated.append(name)
 
     def _check_datatypes(self):
-        """ checks if datatype is valid.
-        datatype of properties is simply initialized with string. Here over
-        properties is iterated and datatype is corrected. """
+        """Checks if the datatype is valid. 
+
+        Iterate over all properties in this datamodel and choose a
+        valid datatype from the original datatype string in the yaml
+        file. Raise a ValueError if no datatype can be found.
+
+        """
 
         for key, value in self.model.items():
             if isinstance(value, db.Property):
@@ -368,7 +375,8 @@ class Parser(object):
                     try:
                         value.datatype = db.__getattribute__(value.datatype)
                     except AttributeError:
-                        raise ValueError("Unknown Datatype.")
+                        raise ValueError(
+                            "Property {} has an unknown datatype: {}".format(value.name, value.datatype))
 
     def _set_recordtypes(self):
         """ properties are defined in first iteration; set remaining as RTs """