Merge branch 'hard-reset' of https://github.com/takluyver/ipython into takluyver-hard-reset

IPython/core/displayhook.py

@@ -319,6 +319,9 b' class DisplayHook(Configurable):'
             except: pass
         self.shell.user_ns['_oh'].clear()
         
+        # Release our own references to objects:
+        self._, self.__, self.___ = '', '', ''
+        
         if '_' not in __builtin__.__dict__:
             self.shell.user_ns.update({'_':None,'__':None, '___':None})
         import gc

IPython/core/interactiveshell.py

@@ -1045,6 +1045,9 b' class InteractiveShell(Configurable, Magic):'
         """
         # Clear histories
         self.history_manager.reset(new_session)
+        
+        # Flush cached output items
+        self.displayhook.flush()
 
         # Reset counter used to index all histories
         self.execution_count = 0
@@ -1069,6 +1072,10 b' class InteractiveShell(Configurable, Magic):'
         # Restore the default and user aliases
         self.alias_manager.clear_aliases()
         self.alias_manager.init_aliases()
+        
+        # Flush the private list of module references kept for script
+        # execution protection
+        self.clear_main_mod_cache()
 
     def reset_selective(self, regex=None):
         """Clear selective variables from internal namespaces based on a

IPython/core/magic.py

@@ -967,12 +967,15 b' Currently the magic system has the following functions:\\n"""'
     def magic_reset(self, parameter_s=''):
         """Resets the namespace by removing all names defined by the user.
 
-        Input/Output history are left around in case you need them.
-
         Parameters
         ----------
           -f : force reset without asking for confirmation.
-
+          
+          -s : 'Soft' reset: Only clears your namespace, leaving history intact.
+          References to objects may be kept. By default (without this option),
+          we do a 'hard' reset, giving you a new session and removing all
+          references to objects from the current session.
+        
         Examples
         --------
         In [6]: a = 1
@@ -985,11 +988,11 b' Currently the magic system has the following functions:\\n"""'
 
         In [9]: %reset -f
 
-        In [10]: 'a' in _ip.user_ns
-        Out[10]: False
+        In [1]: 'a' in _ip.user_ns
+        Out[1]: False
         """
-
-        if parameter_s == '-f':
+        opts, args = self.parse_options(parameter_s,'sh')
+        if 'f' in opts:
             ans = True
         else:
             ans = self.shell.ask_yes_no(
@@ -997,13 +1000,16 b' Currently the magic system has the following functions:\\n"""'
         if not ans:
             print 'Nothing done.'
             return
-        user_ns = self.shell.user_ns
-        for i in self.magic_who_ls():
-            del(user_ns[i])
+        
+        if 's' in opts:                     # Soft reset
+            user_ns = self.shell.user_ns
+            for i in self.magic_who_ls():
+                del(user_ns[i])
             
-        # Also flush the private list of module references kept for script
-        # execution protection
-        self.shell.clear_main_mod_cache()
+        else:                     # Hard reset
+            self.shell.reset(new_session = True)
+            
+        
 
     def magic_reset_selective(self, parameter_s=''):
         """Resets the namespace by removing names defined by the user.

IPython/core/tests/test_magic.py

@@ -379,6 +379,21 b' def test_xmode():'
     for i in range(3):
         _ip.magic("xmode")
     nt.assert_equal(_ip.InteractiveTB.mode, xmode)
+    
+def test_reset_hard():
+    monitor = []
+    class A(object):
+        def __del__(self):
+            monitor.append(1)
+        def __repr__(self):
+            return "<A instance>"
+            
+    _ip.user_ns["a"] = A()
+    _ip.run_cell("a")
+    
+    nt.assert_equal(monitor, [])
+    _ip.magic_reset("-f")
+    nt.assert_equal(monitor, [1])
 
 def doctest_who():
     """doctest for %who