Fix Typo and mutable default argument.

Author: Carreau

ipykernel/ipkernel.py

@@ -243,9 +243,9 @@ def do_execute(self, code, silent, store_history=True,
 
         # Payloads should be retrieved regardless of outcome, so we can both
         # recover partial output (that could have been generated early in a
-        # block, before an error) and clear the payload system always.
+        # block, before an error) and always clear the payload system.
         reply_content[u'payload'] = shell.payload_manager.read_payload()
-        # Be agressive about clearing the payload because we don't want
+        # Be aggressive about clearing the payload because we don't want
         # it to sit in memory until the next execute_request comes in.
         shell.payload_manager.clear_payload()
 

ipykernel/kernelspec.py

@@ -22,7 +22,7 @@
 RESOURCES = pjoin(os.path.dirname(__file__), 'resources')
 
 
-def make_ipkernel_cmd(mod='ipykernel', executable=None, extra_arguments=[], **kw):
+def make_ipkernel_cmd(mod='ipykernel', executable=None, extra_arguments=None, **kw):
     """Build Popen command list for launching an IPython kernel.
 
     Parameters
@@ -43,6 +43,7 @@ def make_ipkernel_cmd(mod='ipykernel', executable=None, extra_arguments=[], **kw
     """
     if executable is None:
         executable = sys.executable
+    extra_arguments = extra_arguments or []
     arguments = [ executable, '-m', mod, '-f', '{connection_file}' ]
     arguments.extend(extra_arguments)