Created context manager for the things injected into __builtin__.

IPython/core/builtin_trap.py

@@ -0,0 +1,104 b''
+#!/usr/bin/env python
+# encoding: utf-8
+"""
+A context manager for managing things injected into :mod:`__builtin__`.
+
+Authors:
+
+* Brian Granger
+"""
+
+#-----------------------------------------------------------------------------
+#  Copyright (C) 2008-2009  The IPython Development Team
+#
+#  Distributed under the terms of the BSD License.  The full license is in
+#  the file COPYING, distributed as part of this software.
+#-----------------------------------------------------------------------------
+
+#-----------------------------------------------------------------------------
+# Imports
+#-----------------------------------------------------------------------------
+
+import __builtin__
+
+from IPython.core.component import Component
+from IPython.core.quitter import Quitter
+
+#-----------------------------------------------------------------------------
+# Classes and functions
+#-----------------------------------------------------------------------------
+
+
+class BuiltinUndefined(object): pass
+BuiltinUndefined = BuiltinUndefined()
+
+
+class BuiltinTrap(Component):
+
+    def __init__(self, parent, name=None, config=None):
+        super(BuiltinTrap, self).__init__(parent, name, config)
+        # Don't just grab parent!!!
+        from IPython.core.iplib import InteractiveShell
+        self.shell = InteractiveShell.get_instances(root=self.root)[0]
+        self._orig_builtins = {}
+
+    def __enter__(self):
+        self.set()
+        # I return self, so callers can use add_builtin in a with clause.
+        return self
+
+    def __exit__(self, type, value, traceback):
+        self.unset()
+        return True
+
+    def add_builtin(self, key, value):
+        """Add a builtin and save the original."""
+        orig = __builtin__.__dict__.get(key, BuiltinUndefined)
+        self._orig_builtins[key] = orig
+        __builtin__.__dict__[key] = value
+
+    def remove_builtin(self, key):
+        """Remove an added builtin and re-set the original."""
+        try:
+            orig = self._orig_builtins.pop(key)
+        except KeyError:
+            pass
+        else:
+            if orig is BuiltinUndefined:
+                del __builtin__.__dict__[key]
+            else:
+                __builtin__.__dict__[key] = orig
+
+    def set(self):
+        """Store ipython references in the __builtin__ namespace."""
+        self.add_builtin('exit', Quitter(self.shell, 'exit'))
+        self.add_builtin('quit', Quitter(self.shell, 'quit'))
+
+        # Recursive reload function
+        try:
+            from IPython.lib import deepreload
+            if self.shell.deep_reload:
+                self.add_builtin('reload', deepreload.reload)
+            else:
+                self.add_builtin('dreload', deepreload.reload)
+            del deepreload
+        except ImportError:
+            pass
+
+        # Keep in the builtins a flag for when IPython is active.  We set it
+        # with setdefault so that multiple nested IPythons don't clobber one
+        # another.  Each will increase its value by one upon being activated,
+        # which also gives us a way to determine the nesting level.
+        __builtin__.__dict__.setdefault('__IPYTHON__active',0)
+
+    def unset(self):
+        """Remove any builtins which might have been added by add_builtins, or
+        restore overwritten ones to their previous values."""
+        for key in self._orig_builtins.keys():
+            self.remove_builtin(key)
+        self._orig_builtins.clear()
+        self._builtins_added = False
+        try:
+            del __builtin__.__dict__['__IPYTHON__active']
+        except KeyError:
+            pass
  No newline at end of file

IPython/core/quitter.py

@@ -0,0 +1,38 b''
+#!/usr/bin/env python
+# encoding: utf-8
+"""
+A simple class for quitting IPython.
+
+Authors:
+
+* Brian Granger
+"""
+
+#-----------------------------------------------------------------------------
+#  Copyright (C) 2008-2009  The IPython Development Team
+#
+#  Distributed under the terms of the BSD License.  The full license is in
+#  the file COPYING, distributed as part of this software.
+#-----------------------------------------------------------------------------
+
+#-----------------------------------------------------------------------------
+# Imports
+#-----------------------------------------------------------------------------
+
+
+class Quitter(object):
+    """Simple class to handle exit, similar to Python 2.5's.
+
+    It handles exiting in an ipython-safe manner, which the one in Python 2.5
+    doesn't do (obviously, since it doesn't know about ipython)."""
+    
+    def __init__(self, shell, name):
+        self.shell = shell
+        self.name = name
+        
+    def __repr__(self):
+        return 'Type %s() to exit.' % self.name
+    __str__ = __repr__
+
+    def __call__(self):
+        self.shell.exit()
  No newline at end of file

IPython/core/component.py

@@ -52,15 +52,19 b' class MetaComponentTracker(type):'
         When a Component or subclass is instantiated, this is called and
         the instance is saved in a WeakValueDictionary for tracking.
         """
-
-        instance = super(MetaComponentTracker, cls).__call__(*args, **kw)
+        instance = cls.__new__(cls, *args, **kw)
+        # Do this before __init__ is called so get_instances works inside
+        # __init__ methods!
         for c in cls.__mro__:
             if issubclass(cls, c) and issubclass(c, Component):
                 c.__numcreated += 1
                 c.__instance_refs[c.__numcreated] = instance
+        if isinstance(instance, cls):
+            cls.__init__(instance, *args, **kw)
+
         return instance
 
-    def get_instances(cls, name=None, root=None):
+    def get_instances(cls, name=None, root=None, classname=None):
         """Get all instances of cls and its subclasses.
 
         Parameters
@@ -69,21 +73,26 b' class MetaComponentTracker(type):'
             Limit to components with this name.
         root : Component or subclass
             Limit to components having this root.
+        classname : str
+            The string name of a class to match exactly.
         """
         instances = cls.__instance_refs.values()
         if name is not None:
             instances = [i for i in instances if i.name == name]
+        if classname is not None:
+            instances = [i for i in instances if i.__class__.__name__ == classname]
         if root is not None:
             instances = [i for i in instances if i.root == root]
         return instances
 
-    def get_instances_by_condition(cls, call, name=None, root=None):
+    def get_instances_by_condition(cls, call, name=None, root=None,
+                                   classname=None):
         """Get all instances of cls, i such that call(i)==True.
 
-        This also takes the ``name`` and ``root`` arguments of
-        :meth:`get_instance`
+        This also takes the ``name`` and ``root`` and ``classname`` 
+        arguments of :meth:`get_instance`
         """
-        return [i for i in cls.get_instances(name, root) if call(i)]
+        return [i for i in cls.get_instances(name, root, classname) if call(i)]
 
 
 class ComponentNameGenerator(object):

IPython/core/embed.py

@@ -23,6 +23,8 b' Notes'
 # Imports
 #-----------------------------------------------------------------------------
 
+from __future__ import with_statement
+
 import sys
 
 from IPython.core import ultratb
@@ -63,7 +65,7 b' class InteractiveShellEmbed(InteractiveShell):'
     def __init__(self, parent=None, config=None, ipythondir=None, usage=None,
                  user_ns=None, user_global_ns=None,
                  banner1=None, banner2=None,
-                 custom_exceptions=((),None), exit_msg=None):
+                 custom_exceptions=((),None), exit_msg=''):
 
         # First we need to save the state of sys.displayhook and
         # sys.ipcompleter so we can restore it when we are done.
@@ -172,7 +174,7 b' class InteractiveShellEmbed(InteractiveShell):'
 
         # Call the embedding code with a stack depth of 1 so it can skip over
         # our call and get the original caller's namespaces.
-        self.embed_mainloop(banner, local_ns, global_ns, 
+        self.mainloop(banner, local_ns, global_ns, 
                             stack_depth=stack_depth)
 
         if self.exit_msg is not None:
@@ -182,6 +184,71 b' class InteractiveShellEmbed(InteractiveShell):'
         self.restore_sys_displayhook()
         self.restore_sys_ipcompleter()
 
+    def mainloop(self,header='',local_ns=None,global_ns=None,stack_depth=0):
+        """Embeds IPython into a running python program.
+
+        Input:
+
+          - header: An optional header message can be specified.
+
+          - local_ns, global_ns: working namespaces. If given as None, the
+          IPython-initialized one is updated with __main__.__dict__, so that
+          program variables become visible but user-specific configuration
+          remains possible.
+
+          - stack_depth: specifies how many levels in the stack to go to
+          looking for namespaces (when local_ns and global_ns are None).  This
+          allows an intermediate caller to make sure that this function gets
+          the namespace from the intended level in the stack.  By default (0)
+          it will get its locals and globals from the immediate caller.
+
+        Warning: it's possible to use this in a program which is being run by
+        IPython itself (via %run), but some funny things will happen (a few
+        globals get overwritten). In the future this will be cleaned up, as
+        there is no fundamental reason why it can't work perfectly."""
+
+        # Get locals and globals from caller
+        if local_ns is None or global_ns is None:
+            call_frame = sys._getframe(stack_depth).f_back
+
+            if local_ns is None:
+                local_ns = call_frame.f_locals
+            if global_ns is None:
+                global_ns = call_frame.f_globals
+
+        # Update namespaces and fire up interpreter
+
+        # The global one is easy, we can just throw it in
+        self.user_global_ns = global_ns
+
+        # but the user/local one is tricky: ipython needs it to store internal
+        # data, but we also need the locals.  We'll copy locals in the user
+        # one, but will track what got copied so we can delete them at exit.
+        # This is so that a later embedded call doesn't see locals from a
+        # previous call (which most likely existed in a separate scope).
+        local_varnames = local_ns.keys()
+        self.user_ns.update(local_ns)
+        #self.user_ns['local_ns'] = local_ns  # dbg
+
+        # Patch for global embedding to make sure that things don't overwrite
+        # user globals accidentally. Thanks to Richard <[e-mail]>
+        # FIXME. Test this a bit more carefully (the if.. is new)
+        if local_ns is None and global_ns is None:
+            self.user_global_ns.update(__main__.__dict__)
+
+        # make sure the tab-completer has the correct frame information, so it
+        # actually completes using the frame's locals/globals
+        self.set_completer_frame()
+
+        with self.builtin_trap:
+            self.interact(header)
+        
+            # now, purge out the user namespace from anything we might have added
+            # from the caller's local namespace
+            delvar = self.user_ns.pop
+            for var in local_varnames:
+                delvar(var,None)
+
 
 _embedded_shell = None
 

IPython/core/iplib.py

@@ -16,6 +16,8 b' Main IPython Component'
 # Imports
 #-----------------------------------------------------------------------------
 
+from __future__ import with_statement
+
 import __main__
 import __builtin__
 import StringIO
@@ -38,6 +40,7 b' from IPython.core import shadowns'
 from IPython.core import history as ipcorehist
 from IPython.core import prefilter
 from IPython.core.autocall import IPyAutocall
+from IPython.core.builtin_trap import BuiltinTrap
 from IPython.core.fakemodule import FakeModule, init_fakemod_dict
 from IPython.core.logger import Logger
 from IPython.core.magic import Magic
@@ -112,28 +115,6 b' class SpaceInInput(exceptions.Exception): pass'
 
 class Bunch: pass
 
-class BuiltinUndefined: pass
-BuiltinUndefined = BuiltinUndefined()
-
-
-class Quitter(object):
-    """Simple class to handle exit, similar to Python 2.5's.
-
-    It handles exiting in an ipython-safe manner, which the one in Python 2.5
-    doesn't do (obviously, since it doesn't know about ipython)."""
-    
-    def __init__(self, shell, name):
-        self.shell = shell
-        self.name = name
-        
-    def __repr__(self):
-        return 'Type %s() to exit.' % self.name
-    __str__ = __repr__
-
-    def __call__(self):
-        self.shell.exit()
-
-
 class InputList(list):
     """Class to store user input.
 
@@ -340,7 +321,6 b' class InteractiveShell(Component, Magic):'
         self.hooks.late_startup_hook()
 
     def cleanup(self):
-        self.remove_builtins()
         self.restore_sys_module_state()
 
     #-------------------------------------------------------------------------
@@ -834,10 +814,7 b' class InteractiveShell(Component, Magic):'
             self.magic_alias(alias)
 
     def init_builtins(self):
-        # track which builtins we add, so we can clean up later
-        self._orig_builtins = {}
-        self._builtins_added = False
-        self.add_builtins()
+        self.builtin_trap = BuiltinTrap(self)
 
     def init_shadow_hist(self):
         try:
@@ -1075,60 +1052,6 b' class InteractiveShell(Component, Magic):'
         except ImportError:
             warn('help() not available - check site.py')
 
-    def add_builtin(self, key, value):
-        """Add a builtin and save the original."""
-        orig = __builtin__.__dict__.get(key, BuiltinUndefined)
-        self._orig_builtins[key] = orig
-        __builtin__.__dict__[key] = value
-
-    def remove_builtin(self, key):
-        """Remove an added builtin and re-set the original."""
-        try:
-            orig = self._orig_builtins.pop(key)
-        except KeyError:
-            pass
-        else:
-            if orig is BuiltinUndefined:
-                del __builtin__.__dict__[key]
-            else:
-                __builtin__.__dict__[key] = orig
-
-    def add_builtins(self):
-        """Store ipython references into the __builtin__ namespace.
-
-        We strive to modify the __builtin__ namespace as little as possible.
-        """
-        if not self._builtins_added:
-            self.add_builtin('exit', Quitter(self,'exit'))
-            self.add_builtin('quit', Quitter(self,'quit'))
-
-            # Recursive reload function
-            try:
-                from IPython.lib import deepreload
-                if self.deep_reload:
-                    self.add_builtin('reload', deepreload.reload)
-                else:
-                    self.add_builtin('dreload', deepreload.reload)
-                del deepreload
-            except ImportError:
-                pass
-
-            # Keep in the builtins a flag for when IPython is active.  We set it
-            # with setdefault so that multiple nested IPythons don't clobber one
-            # another.  Each will increase its value by one upon being activated,
-            # which also gives us a way to determine the nesting level.
-            __builtin__.__dict__.setdefault('__IPYTHON__active',0)
-            self._builtins_added = True
-
-    def remove_builtins(self):
-        """Remove any builtins which might have been added by add_builtins, or
-        restore overwritten ones to their previous values."""
-        if self._builtins_added:
-            for key in self._orig_builtins.keys():
-                self.remove_builtin(key)
-            self._orig_builtins.clear()
-            self._builtins_added = False
-
     def save_sys_module_state(self):
         """Save the state of hooks in the sys module.
 
@@ -1328,7 +1251,9 b' class InteractiveShell(Component, Magic):'
             error("Magic function `%s` not found." % magic_name)
         else:
             magic_args = self.var_expand(magic_args,1)
-            return fn(magic_args)
+            with self.builtin_trap:
+                result = fn(magic_args)
+            return result
 
     def define_magic(self, magicname, func):
         """Expose own function as magic function for ipython 
@@ -1423,6 +1348,7 b' class InteractiveShell(Component, Magic):'
 
     def ex(self, cmd):
         """Execute a normal python statement in user namespace."""
+        with self.builtin_trap:
         exec cmd in self.user_global_ns, self.user_ns
 
     def ev(self, expr):
@@ -1430,7 +1356,9 b' class InteractiveShell(Component, Magic):'
 
         Returns the result of evaluation
         """
-        return eval(expr, self.user_global_ns, self.user_ns)
+        with self.builtin_trap:
+            result = eval(expr, self.user_global_ns, self.user_ns)
+        return result
 
     def getoutput(self, cmd):
         return getoutput(self.var_expand(cmd,depth=2),
@@ -1468,6 +1396,8 b' class InteractiveShell(Component, Magic):'
         Out[10]: ['x.ljust', 'x.lower', 'x.lstrip']
         """
         
+        # Inject names into __builtin__ so we can complete on the added names.
+        with self.builtin_trap:
         complete = self.Completer.complete
         state = 0
         # use a dict so we get unique keys, since ipyhton's multiple
@@ -1875,6 +1805,8 b' class InteractiveShell(Component, Magic):'
         If an optional banner argument is given, it will override the
         internally created default banner.
         """
+        
+        with self.builtin_trap:
         if self.c:  # Emulate Python's -c option
             self.exec_init_cmd()
 
@@ -1909,77 +1841,6 b' class InteractiveShell(Component, Magic):'
         if not self.interactive:
             self.ask_exit()
 
-    def embed_mainloop(self,header='',local_ns=None,global_ns=None,stack_depth=0):
-        """Embeds IPython into a running python program.
-
-        Input:
-
-          - header: An optional header message can be specified.
-
-          - local_ns, global_ns: working namespaces. If given as None, the
-          IPython-initialized one is updated with __main__.__dict__, so that
-          program variables become visible but user-specific configuration
-          remains possible.
-
-          - stack_depth: specifies how many levels in the stack to go to
-          looking for namespaces (when local_ns and global_ns are None).  This
-          allows an intermediate caller to make sure that this function gets
-          the namespace from the intended level in the stack.  By default (0)
-          it will get its locals and globals from the immediate caller.
-
-        Warning: it's possible to use this in a program which is being run by
-        IPython itself (via %run), but some funny things will happen (a few
-        globals get overwritten). In the future this will be cleaned up, as
-        there is no fundamental reason why it can't work perfectly."""
-
-        # Get locals and globals from caller
-        if local_ns is None or global_ns is None:
-            call_frame = sys._getframe(stack_depth).f_back
-
-            if local_ns is None:
-                local_ns = call_frame.f_locals
-            if global_ns is None:
-                global_ns = call_frame.f_globals
-
-        # Update namespaces and fire up interpreter
-
-        # The global one is easy, we can just throw it in
-        self.user_global_ns = global_ns
-
-        # but the user/local one is tricky: ipython needs it to store internal
-        # data, but we also need the locals.  We'll copy locals in the user
-        # one, but will track what got copied so we can delete them at exit.
-        # This is so that a later embedded call doesn't see locals from a
-        # previous call (which most likely existed in a separate scope).
-        local_varnames = local_ns.keys()
-        self.user_ns.update(local_ns)
-        #self.user_ns['local_ns'] = local_ns  # dbg
-
-        # Patch for global embedding to make sure that things don't overwrite
-        # user globals accidentally. Thanks to Richard <[e-mail]>
-        # FIXME. Test this a bit more carefully (the if.. is new)
-        if local_ns is None and global_ns is None:
-            self.user_global_ns.update(__main__.__dict__)
-
-        # make sure the tab-completer has the correct frame information, so it
-        # actually completes using the frame's locals/globals
-        self.set_completer_frame()
-
-        # before activating the interactive mode, we need to make sure that
-        # all names in the builtin namespace needed by ipython point to
-        # ourselves, and not to other instances.
-        self.add_builtins()
-
-        self.interact(header)
-        
-        # now, purge out the user namespace from anything we might have added
-        # from the caller's local namespace
-        delvar = self.user_ns.pop
-        for var in local_varnames:
-            delvar(var,None)
-        # and clean builtins we may have overridden
-        self.remove_builtins()
-
     def interact_prompt(self):
         """ Print the prompt (in read-eval-print loop) 
 
@@ -2377,6 +2238,7 b' class InteractiveShell(Component, Magic):'
         lines = lines.splitlines()
         more = 0
     
+        with self.builtin_trap:
         for line in lines:
             # skip blank lines so we don't mess up the prompt counter, but do
             # NOT skip even a blank line if we are in a code block (more is