Table.__repr__: Fix for sparse data with < 5 instances

Scipy does not support indexing table[:5] if table has less than 5 rows.

Author: nikicc

Orange/data/table.py

@@ -803,7 +803,10 @@ def __str__(self):
         return "[" + ",\n ".join(str(ex) for ex in self)
 
     def __repr__(self):
-        s = "[" + ",\n ".join(repr(ex) for ex in self[:5])
+        head = 5
+        if sp.issparse(self.X):
+            head = min(self.X.shape[0], head)
+        s = "[" + ",\n ".join(repr(ex) for ex in self[:head])
         if len(self) > 5:
             s += ",\n ..."
         s += "\n]"