improving Needs to do not load again packages already loaded

Author: mmatera

mathics/builtin/attributes.py

@@ -166,15 +166,15 @@ def apply(self, symbols, evaluation):
         protected = Symbol("System`Protected")
         items = []
 
-        if isinstance(symbols ,Symbol):
+        if isinstance(symbols, Symbol):
             symbols = [symbols]
         elif isinstance(symbols, String):
             symbols = [symbols]
         elif isinstance(symbols, Expression):
             if symbols.get_head_name() in ("System`Sequence", "System`List"):
                 symbols = symbols.get_leaves()
             else:
-                evaluation.message('Protect', 'ssym', symbol)
+                evaluation.message('Protect', 'ssym', symbols)
                 return Symbol("Null")
 
         for symbol in symbols:

mathics/builtin/system.py

@@ -237,11 +237,6 @@ class Packages(Predefined):
 
     name = "$Packages"
     rules = {'$Packages': '{"CombinatoricaOld`", "ImportExport`",  "XML`","Internal`", "System`", "Global`"}',}
-    # def evaluate(self, evaluation):
-    #    return Expression(
-    #        "List",
-    #        *(String(name) for name in evaluation.definitions.get_package_names()),
-    #    )
 
 
 class ParentProcessID(Predefined):