Fix grammar and spacing in a warning message

IPython/core/magics/extension.py

@@ -1,96 +1,96 b''
 """Implementation of magic functions for the extension machinery.
 """
 from __future__ import print_function
 #-----------------------------------------------------------------------------
 #  Copyright (c) 2012 The IPython Development Team.
 #
 #  Distributed under the terms of the Modified BSD License.
 #
 #  The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # Stdlib
 import os
 
 # Our own packages
 from IPython.core.error import UsageError
 from IPython.core.magic import Magics, magics_class, line_magic
 from  warnings import warn
 
 #-----------------------------------------------------------------------------
 # Magic implementation classes
 #-----------------------------------------------------------------------------
 
 @magics_class
 class ExtensionMagics(Magics):
     """Magics to manage the IPython extensions system."""
 
     @line_magic
     def install_ext(self, parameter_s=''):
         """Download and install an extension from a URL, e.g.::
 
             %install_ext https://bitbucket.org/birkenfeld/ipython-physics/raw/d1310a2ab15d/physics.py
 
         The URL should point to an importable Python module - either a .py file
         or a .zip file.
 
         Parameters:
 
           -n filename : Specify a name for the file, rather than taking it from
                         the URL.
         """
-        warn("%install_ext` is deprecated, please distribute your extension(s)"
-             "as a python packages.", UserWarning)
+        warn("%install_ext` is deprecated, please distribute your extension "
+             "as a python package.", UserWarning)
         opts, args = self.parse_options(parameter_s, 'n:')
         try:
             filename = self.shell.extension_manager.install_extension(args,
                                                                  opts.get('n'))
         except ValueError as e:
             print(e)
             return
 
         filename = os.path.basename(filename)
         print("Installed %s. To use it, type:" % filename)
         print("  %%load_ext %s" % os.path.splitext(filename)[0])
 
 
     @line_magic
     def load_ext(self, module_str):
         """Load an IPython extension by its module name."""
         if not module_str:
             raise UsageError('Missing module name.')
         res = self.shell.extension_manager.load_extension(module_str)
         
         if res == 'already loaded':
             print("The %s extension is already loaded. To reload it, use:" % module_str)
             print("  %reload_ext", module_str)
         elif res == 'no load function':
             print("The %s module is not an IPython extension." % module_str)
 
     @line_magic
     def unload_ext(self, module_str):
         """Unload an IPython extension by its module name.
         
         Not all extensions can be unloaded, only those which define an
         ``unload_ipython_extension`` function.
         """
         if not module_str:
             raise UsageError('Missing module name.')
         
         res = self.shell.extension_manager.unload_extension(module_str)
         
         if res == 'no unload function':
             print("The %s extension doesn't define how to unload it." % module_str)
         elif res == "not loaded":
             print("The %s extension is not loaded." % module_str)
 
     @line_magic
     def reload_ext(self, module_str):
         """Reload an IPython extension by its module name."""
         if not module_str:
             raise UsageError('Missing module name.')
         self.shell.extension_manager.reload_extension(module_str)