Fix sorting

djaosdb/caosdb_client.py

@@ -37,7 +37,7 @@ class CountResult(Result):
         return iter(self._results)
 
 def _sort_key(x, field):
-    return x[field] or ""
+    return str(x[field] or "")
 
 class FindResult(Result):
 
@@ -52,8 +52,9 @@ class FindResult(Result):
         if columns is not None:
             if sort:
                 fkey = list(sort)[0]
+                reverse = sort[fkey] < 0
                 named_columns = [dict(zip(columns, row)) for row in rows]
-                named_columns.sort(key=lambda x: _sort_key(x, fkey), reverse=sort[fkey] < 0)
+                named_columns.sort(key=lambda x: _sort_key(x, fkey), reverse=reverse)
                 self._results = named_columns[skip:upper]
             else:
                 self._results = []