Fixes #11068 : Cleanup extra logic that handle python <=3.3 in IPython/core/extensions.py

IPython/core/extensions.py

@@ -1,155 +1,150 b''
 # encoding: utf-8
 """A class for managing IPython extensions."""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 import os
 import os.path
 import sys
-from importlib import import_module
+from importlib import import_module, reload
 
 from traitlets.config.configurable import Configurable
 from IPython.utils.path import ensure_dir_exists, compress_user
 from IPython.utils.decorators import undoc
 from traitlets import Instance
 
-try:
-    from importlib import reload
-except ImportError :
-    ## deprecated since 3.4
-    from imp import reload
 
 #-----------------------------------------------------------------------------
 # Main class
 #-----------------------------------------------------------------------------
 
 class ExtensionManager(Configurable):
     """A class to manage IPython extensions.
 
     An IPython extension is an importable Python module that has
     a function with the signature::
 
         def load_ipython_extension(ipython):
             # Do things with ipython
 
     This function is called after your extension is imported and the
     currently active :class:`InteractiveShell` instance is passed as
     the only argument.  You can do anything you want with IPython at
     that point, including defining new magic and aliases, adding new
     components, etc.
     
     You can also optionally define an :func:`unload_ipython_extension(ipython)`
     function, which will be called if the user unloads or reloads the extension.
     The extension manager will only call :func:`load_ipython_extension` again
     if the extension is reloaded.
 
     You can put your extension modules anywhere you want, as long as
     they can be imported by Python's standard import mechanism.  However,
     to make it easy to write extensions, you can also put your extensions
     in ``os.path.join(self.ipython_dir, 'extensions')``.  This directory
     is added to ``sys.path`` automatically.
     """
 
     shell = Instance('IPython.core.interactiveshell.InteractiveShellABC', allow_none=True)
 
     def __init__(self, shell=None, **kwargs):
         super(ExtensionManager, self).__init__(shell=shell, **kwargs)
         self.shell.observe(
             self._on_ipython_dir_changed, names=('ipython_dir',)
         )
         self.loaded = set()
 
     @property
     def ipython_extension_dir(self):
         return os.path.join(self.shell.ipython_dir, u'extensions')
 
     def _on_ipython_dir_changed(self, change):
         ensure_dir_exists(self.ipython_extension_dir)
 
     def load_extension(self, module_str):
         """Load an IPython extension by its module name.
 
         Returns the string "already loaded" if the extension is already loaded,
         "no load function" if the module doesn't have a load_ipython_extension
         function, or None if it succeeded.
         """
         if module_str in self.loaded:
             return "already loaded"
 
         from IPython.utils.syspathcontext import prepended_to_syspath
 
         with self.shell.builtin_trap:
             if module_str not in sys.modules:
                 with prepended_to_syspath(self.ipython_extension_dir):
                     mod = import_module(module_str)
                     if mod.__file__.startswith(self.ipython_extension_dir):
                         print(("Loading extensions from {dir} is deprecated. "
                                "We recommend managing extensions like any "
                                "other Python packages, in site-packages.").format(
                               dir=compress_user(self.ipython_extension_dir)))
             mod = sys.modules[module_str]
             if self._call_load_ipython_extension(mod):
                 self.loaded.add(module_str)
             else:
                 return "no load function"
 
     def unload_extension(self, module_str):
         """Unload an IPython extension by its module name.
 
         This function looks up the extension's name in ``sys.modules`` and
         simply calls ``mod.unload_ipython_extension(self)``.
         
         Returns the string "no unload function" if the extension doesn't define
         a function to unload itself, "not loaded" if the extension isn't loaded,
         otherwise None.
         """
         if module_str not in self.loaded:
             return "not loaded"
         
         if module_str in sys.modules:
             mod = sys.modules[module_str]
             if self._call_unload_ipython_extension(mod):
                 self.loaded.discard(module_str)
             else:
                 return "no unload function"
 
     def reload_extension(self, module_str):
         """Reload an IPython extension by calling reload.
 
         If the module has not been loaded before,
         :meth:`InteractiveShell.load_extension` is called. Otherwise
         :func:`reload` is called and then the :func:`load_ipython_extension`
         function of the module, if it exists is called.
         """
         from IPython.utils.syspathcontext import prepended_to_syspath
 
         if (module_str in self.loaded) and (module_str in sys.modules):
             self.unload_extension(module_str)
             mod = sys.modules[module_str]
             with prepended_to_syspath(self.ipython_extension_dir):
                 reload(mod)
             if self._call_load_ipython_extension(mod):
                 self.loaded.add(module_str)
         else:
             self.load_extension(module_str)
 
     def _call_load_ipython_extension(self, mod):
         if hasattr(mod, 'load_ipython_extension'):
             mod.load_ipython_extension(self.shell)
             return True
 
     def _call_unload_ipython_extension(self, mod):
         if hasattr(mod, 'unload_ipython_extension'):
             mod.unload_ipython_extension(self.shell)
             return True
 
     @undoc
     def install_extension(self, url, filename=None):
         """
         Deprecated.
         """
         # Ensure the extension directory exists
         raise DeprecationWarning(
             '`install_extension` and the `install_ext` magic have been deprecated since IPython 4.0'
             'Use pip or other package managers to manage ipython extensions.')