Completed work on pretty.py extension.

There is still not any testing, but I have to move on...

IPython/extensions/pretty.py

@@ -4,8 +4,13 b' To enable this extension in your configuration'
 file, add the following to :file:`ipython_config.py`::
 
     c.Global.extensions = ['IPython.extensions.pretty']
+    def dict_pprinter(obj, p, cycle):
+        return p.text("<dict>")
     c.PrettyResultDisplay.verbose = True
-    c.PrettyResultDisplay.defaults = [
+    c.PrettyResultDisplay.defaults_for_type = [
+        (dict, dict_pprinter)
+    ]
+    c.PrettyResultDisplay.defaults_for_type_by_name = [
         ('numpy', 'dtype', 'IPython.extensions.pretty.dtype_pprinter')
     ]
 
@@ -42,28 +47,50 b' from IPython.utils.importstring import import_item'
 # Code
 #-----------------------------------------------------------------------------
 
+
 _loaded = False
 
 
 class PrettyResultDisplay(Component):
+    """A component for pretty printing on steroids."""
 
     verbose = Bool(False, config=True)
+
+    # A list of (type, func_name), like
+    # [(dict, 'my_dict_printer')]
+    # The final argument can also be a callable
+    defaults_for_type = List(default_value=[], config=True)
+
     # A list of (module_name, type_name, func_name), like
     # [('numpy', 'dtype', 'IPython.extensions.pretty.dtype_pprinter')]
-    defaults = List(default_value=[], config=True)
+    # The final argument can also be a callable
+    defaults_for_type_by_name = List(default_value=[], config=True)
 
     def __init__(self, parent, name=None, config=None):
         super(PrettyResultDisplay, self).__init__(parent, name=name, config=config)
-        self.setup_defaults()
+        self._setup_defaults()
 
-    def setup_defaults(self):
+    def _setup_defaults(self):
         """Initialize the default pretty printers."""
-        for type_module, type_name, func_name in self.defaults:
-            func = import_item(func_name)
+        for typ, func_name in self.defaults_for_type:
+            func = self._resolve_func_name(func_name)
+            self.for_type(typ, func)
+        for type_module, type_name, func_name in self.defaults_for_type_by_name:
+            func = self._resolve_func_name(func_name)
             self.for_type_by_name(type_module, type_name, func)
 
-    # Access other components like this rather than by regular attribute
-    # access.
+    def _resolve_func_name(self, func_name):
+        if callable(func_name):
+            return func_name
+        elif isinstance(func_name, basestring):
+            return import_item(func_name)
+        else:
+            raise TypeError('func_name must be a str or callable, got: %r' % func_name)
+
+    # Access other components like this rather than by a regular attribute.
+    # This won't lookup the InteractiveShell object until it is used and
+    # then it is cached.  This is both efficient and couples this class 
+    # more loosely to InteractiveShell.
     @auto_attr
     def shell(self):
         return Component.get_instances(
@@ -93,8 +120,7 b' class PrettyResultDisplay(Component):'
 
     def for_type_by_name(self, type_module, type_name, func):
         """Add a pretty printer for a type by its name and module name."""
-        print type_module, type_name, func
-        return pretty.for_type_by_name(type_name, type_name, func)
+        return pretty.for_type_by_name(type_module, type_name, func)
 
 
 #-----------------------------------------------------------------------------
@@ -103,6 +129,7 b' class PrettyResultDisplay(Component):'
 
 
 def load_ipython_extension(ip):
+    """Load the extension in IPython as a hook."""
     global _loaded
     if not _loaded:
         prd = PrettyResultDisplay(ip, name='pretty_result_display')
@@ -110,6 +137,7 b' def load_ipython_extension(ip):'
         _loaded = True
 
 def unload_ipython_extension(ip):
+    """Unload the extension."""
     # The hook system does not have a way to remove a hook so this is a pass
     pass
 
@@ -124,6 +152,7 b' def dtype_pprinter(obj, p, cycle):'
     """
     if cycle:
         return p.text('dtype(...)')
+    if hasattr(obj, 'fields'):
     if obj.fields is None:
         p.text(repr(obj))
     else:

docs/source/development/reorg.txt

@@ -23,11 +23,16 b' Subpackage descriptions'
   this code will either i) be revived by someone willing to maintain it with
   tests and docs and re-included into IPython or 2) be removed from IPython
   proper, but put into a separate third-party Python package. No new code will
-  be allowed here.
+  be allowed here. If your favorite extension has been moved here please
+  contact the IPython developer mailing list to help us determine the best
+  course of action.
 
 * :mod:`IPython.extensions`.  This package contains fully supported IPython
   extensions.  These extensions adhere to the official IPython extension API
   and can be enabled by adding them to a field in the configuration file.
+  If your extension is no longer in this location, please look in
+  :mod:`IPython.quarantine` and :mod:`IPython.deathrow` and contact the
+  IPython developer mailing list.
 
 * :mod:`IPython.external`. This package contains third party packages and
   modules that IPython ships internally to reduce the number of dependencies.
@@ -49,7 +54,9 b' Subpackage descriptions'
 * :mod:`IPython.quarantine`. This is for code that doesn't meet IPython's
   standards, but that we plan on keeping. To be moved out of this sub-package
   a module needs to have approval of the core IPython developers, tests and
-  documentation.
+  documentation. If your favorite extension has been moved here please contact
+  the IPython developer mailing list to help us determine the best course of
+  action.
 
 * :mod:`IPython.scripts`.  This package contains a variety of top-level
   command line scripts.  Eventually, these should be moved to the