fix Needs

Author: mmatera

mathics/builtin/files.py

@@ -4773,11 +4773,11 @@ def apply(self, context, evaluation):
             evaluation.message('Needs', 'ctx', Expression(
                 'Needs', context), 1, '`')
             return
-
-        # TODO
-        # if Expression('MemberQ', context, Symbol('$Packages')).is_true():
-        #    # Already loaded
-        #    return Symbol('Null')
+        test_loaded = Expression('MemberQ', Symbol('$Packages'), context)
+        test_loaded = test_loaded.evaluate(evaluation)
+        if test_loaded.is_true():
+            # Already loaded
+            return Symbol('Null')
 
         result = Expression('Get', context).evaluate(evaluation)
 

mathics/core/evaluation.py

@@ -337,7 +337,6 @@ def evaluate():
                 else:
                     raise
             except WLThrowInterrupt as ti:
-                print("query: ", query)
                 if ti.tag:
                     self.exc_result = Expression("Hold",
                                                  Expression("Throw",