Get rid of global _loaded flags in extensions

IPython/extensions/autoreload.py

@@ -514,14 +514,9 class AutoreloadMagics(Magics):
             pass
 
 
-_loaded = False
-
-
 def load_ipython_extension(ip):
     """Load the extension in IPython."""
-    global _loaded
-    if not _loaded:
+    if 'autoreload' not in ip.extension_manager.loaded:
         auto_reload = AutoreloadMagics(ip)
         ip.register_magics(auto_reload)
         ip.set_hook('pre_run_code_hook', auto_reload.pre_run_code_hook)
-        _loaded = True

IPython/extensions/cythonmagic.py

@@ -273,11 +273,8 class CythonMagics(Magics):
         html = '\n'.join(l for l in html.splitlines() if not r.match(l))
         return html
 
-_loaded = False
 
 def load_ipython_extension(ip):
     """Load the extension in IPython."""
-    global _loaded
-    if not _loaded:
+    if 'cythonmagic' not in ip.extension_manager.loaded:
         ip.register_magics(CythonMagics)
-        _loaded = True

IPython/extensions/octavemagic.py

@@ -362,10 +362,7 __doc__ = __doc__.format(
     )
 
 
-_loaded = False
 def load_ipython_extension(ip):
     """Load the extension in IPython."""
-    global _loaded
-    if not _loaded:
+    if 'octavemagic' not in ip.extension_manager.loaded:
         ip.register_magics(OctaveMagics)
-        _loaded = True

IPython/extensions/rmagic.py

@@ -588,10 +588,7 __doc__ = __doc__.format(
 )
 
 
-_loaded = False
 def load_ipython_extension(ip):
     """Load the extension in IPython."""
-    global _loaded
-    if not _loaded:
+    if 'rmagic' not in ip.extension_manager.loaded:
         ip.register_magics(RMagics)
-        _loaded = True

IPython/extensions/storemagic.py

@@ -209,12 +209,7 class StoreMagics(Magics):
                 print "Stored '%s' (%s)" % (args[0], obj.__class__.__name__)
 
 
-_loaded = False
-
-
 def load_ipython_extension(ip):
     """Load the extension in IPython."""
-    global _loaded
-    if not _loaded:
+    if 'storemagic' not in ip.extension_manager.loaded:
         ip.register_magics(StoreMagics)
-        _loaded = True