Fixing missing metaclass in KernelManagerABC.

IPython/zmq/kernelmanagerabc.py

@@ -1,399 +1,401 b''
 """Abstract base classes for kernel manager and channels."""
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2013  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # Standard library imports.
 import abc
 
 #-----------------------------------------------------------------------------
 # Channels
 #-----------------------------------------------------------------------------
 
 
 class ChannelABC(object):
     """A base class for all channel ABCs."""
 
     __metaclass__ = abc.ABCMeta
 
     @abc.abstractmethod
     def start(self):
         pass
 
     @abc.abstractmethod
     def stop(self):
         pass
 
     @abc.abstractmethod
     def is_alive(self):
         pass
 
 
 class ShellChannelABC(ChannelABC):
     """The DEALER channel for issues request/replies to the kernel.
     """
 
     @abc.abstractproperty
     def allow_stdin(self):
         pass
 
     @abc.abstractmethod
     def execute(self, code, silent=False, store_history=True,
                 user_variables=None, user_expressions=None, allow_stdin=None):
         """Execute code in the kernel.
 
         Parameters
         ----------
         code : str
             A string of Python code.
 
         silent : bool, optional (default False)
             If set, the kernel will execute the code as quietly possible, and
             will force store_history to be False.
 
         store_history : bool, optional (default True)
             If set, the kernel will store command history.  This is forced
             to be False if silent is True.
 
         user_variables : list, optional
             A list of variable names to pull from the user's namespace.  They
             will come back as a dict with these names as keys and their
             :func:`repr` as values.
 
         user_expressions : dict, optional
             A dict mapping names to expressions to be evaluated in the user's
             dict. The expression values are returned as strings formatted using
             :func:`repr`.
 
         allow_stdin : bool, optional (default self.allow_stdin)
             Flag for whether the kernel can send stdin requests to frontends.
 
             Some frontends (e.g. the Notebook) do not support stdin requests. 
             If raw_input is called from code executed from such a frontend, a
             StdinNotImplementedError will be raised.
 
         Returns
         -------
         The msg_id of the message sent.
         """
         pass
 
     @abc.abstractmethod
     def complete(self, text, line, cursor_pos, block=None):
         """Tab complete text in the kernel's namespace.
 
         Parameters
         ----------
         text : str
             The text to complete.
         line : str
             The full line of text that is the surrounding context for the
             text to complete.
         cursor_pos : int
             The position of the cursor in the line where the completion was
             requested.
         block : str, optional
             The full block of code in which the completion is being requested.
 
         Returns
         -------
         The msg_id of the message sent.
         """
         pass
 
     @abc.abstractmethod
     def object_info(self, oname, detail_level=0):
         """Get metadata information about an object.
 
         Parameters
         ----------
         oname : str
             A string specifying the object name.
         detail_level : int, optional
             The level of detail for the introspection (0-2)
 
         Returns
         -------
         The msg_id of the message sent.
         """
         pass
 
     @abc.abstractmethod
     def history(self, raw=True, output=False, hist_access_type='range', **kwargs):
         """Get entries from the history list.
 
         Parameters
         ----------
         raw : bool
             If True, return the raw input.
         output : bool
             If True, then return the output as well.
         hist_access_type : str
             'range' (fill in session, start and stop params), 'tail' (fill in n)
              or 'search' (fill in pattern param).
 
         session : int
             For a range request, the session from which to get lines. Session
             numbers are positive integers; negative ones count back from the
             current session.
         start : int
             The first line number of a history range.
         stop : int
             The final (excluded) line number of a history range.
 
         n : int
             The number of lines of history to get for a tail request.
 
         pattern : str
             The glob-syntax pattern for a search request.
 
         Returns
         -------
         The msg_id of the message sent.
         """
         pass
 
     @abc.abstractmethod
     def kernel_info(self):
         """Request kernel info."""
         pass
 
     @abc.abstractmethod
     def shutdown(self, restart=False):
         """Request an immediate kernel shutdown.
 
         Upon receipt of the (empty) reply, client code can safely assume that
         the kernel has shut down and it's safe to forcefully terminate it if
         it's still alive.
 
         The kernel will send the reply via a function registered with Python's
         atexit module, ensuring it's truly done as the kernel is done with all
         normal operation.
         """
         pass
 
 
 class IOPubChannelABC(ChannelABC):
     """The SUB channel which listens for messages that the kernel publishes."""
 
 
     @abc.abstractmethod
     def flush(self, timeout=1.0):
         """Immediately processes all pending messages on the SUB channel.
 
         Callers should use this method to ensure that :method:`call_handlers`
         has been called for all messages that have been received on the
         0MQ SUB socket of this channel.
 
         This method is thread safe.
 
         Parameters
         ----------
         timeout : float, optional
             The maximum amount of time to spend flushing, in seconds. The
             default is one second.
         """
         pass
 
 
 class StdInChannelABC(ChannelABC):
     """A reply channel to handle raw_input requests that the kernel makes."""
 
     @abc.abstractmethod
     def input(self, string):
         """Send a string of raw input to the kernel."""
         pass
 
 
 class HBChannelABC(ChannelABC):
     """The heartbeat channel which monitors the kernel heartbeat."""
 
     @abc.abstractproperty
     def time_to_dead(self):
         pass
 
     @abc.abstractmethod
     def pause(self):
         """Pause the heartbeat."""
         pass
 
     @abc.abstractmethod
     def unpause(self):
         """Unpause the heartbeat."""
         pass
 
     @abc.abstractmethod
     def is_beating(self):
         """Is the heartbeat running and responsive (and not paused)."""
         pass
 
 
 #-----------------------------------------------------------------------------
 # Main kernel manager class
 #-----------------------------------------------------------------------------
 
 class KernelManagerABC(object):
     """ Manages a kernel for a frontend."""
 
+    __metaclass__ = abc.ABCMeta
+
     @abc.abstractproperty
     def kernel(self):
         pass
 
     @abc.abstractproperty
     def shell_channel_class(self):
         pass
 
     @abc.abstractproperty
     def iopub_channel_class(self):
         pass
 
     @abc.abstractproperty
     def hb_channel_class(self):
         pass
 
     @abc.abstractproperty
     def stdin_channel_class(self):
         pass
 
     #--------------------------------------------------------------------------
     # Channel management methods:
     #--------------------------------------------------------------------------
 
     @abc.abstractmethod
     def start_channels(self, shell=True, iopub=True, stdin=True, hb=True):
         """Starts the channels for this kernel.
 
         This will create the channels if they do not exist and then start
         them. If port numbers of 0 are being used (random ports) then you
         must first call :method:`start_kernel`. If the channels have been
         stopped and you call this, :class:`RuntimeError` will be raised.
         """
         pass
 
     @abc.abstractmethod
     def stop_channels(self):
         """Stops all the running channels for this kernel."""
         pass
 
     @abc.abstractproperty
     def channels_running(self):
         """Are any of the channels created and running?"""
         pass
 
     @abc.abstractproperty
     def shell_channel(self):
         """Get the REQ socket channel object to make requests of the kernel."""
         pass
 
     @abc.abstractproperty
     def iopub_channel(self):
         """Get the SUB socket channel object."""
         pass
 
     @abc.abstractproperty
     def stdin_channel(self):
         """Get the REP socket channel object to handle stdin (raw_input)."""
         pass
 
     @abc.abstractproperty
     def hb_channel(self):
         """Get the heartbeat socket channel object to check that the
         kernel is alive."""
         pass
 
     #--------------------------------------------------------------------------
     # Kernel management.
     #--------------------------------------------------------------------------
 
     @abc.abstractmethod
     def start_kernel(self, **kw):
         """Starts a kernel process and configures the manager to use it.
 
         If random ports (port=0) are being used, this method must be called
         before the channels are created.
 
         Parameters:
         -----------
         launcher : callable, optional (default None)
              A custom function for launching the kernel process (generally a
              wrapper around ``entry_point.base_launch_kernel``). In most cases,
              it should not be necessary to use this parameter.
 
         **kw : optional
              See respective options for IPython and Python kernels.
         """
         pass
 
     @abc.abstractmethod
     def shutdown_kernel(self, now=False, restart=False):
         """ Attempts to the stop the kernel process cleanly."""
         pass
 
     @abc.abstractmethod
     def restart_kernel(self, now=False, **kw):
         """Restarts a kernel with the arguments that were used to launch it.
 
         If the old kernel was launched with random ports, the same ports will be
         used for the new kernel.
 
         Parameters
         ----------
         now : bool, optional
             If True, the kernel is forcefully restarted *immediately*, without
             having a chance to do any cleanup action.  Otherwise the kernel is
             given 1s to clean up before a forceful restart is issued.
 
             In all cases the kernel is restarted, the only difference is whether
             it is given a chance to perform a clean shutdown or not.
 
         **kw : optional
             Any options specified here will replace those used to launch the
             kernel.
         """
         pass
 
     @abc.abstractproperty
     def has_kernel(self):
         """Returns whether a kernel process has been specified for the kernel
         manager.
         """
         pass
 
     @abc.abstractmethod
     def kill_kernel(self):
         """ Kill the running kernel.
 
         This method blocks until the kernel process has terminated.
         """
         pass
 
     @abc.abstractmethod
     def interrupt_kernel(self):
         """ Interrupts the kernel.
 
         Unlike ``signal_kernel``, this operation is well supported on all
         platforms.
         """
         pass
 
     @abc.abstractmethod
     def signal_kernel(self, signum):
         """ Sends a signal to the kernel.
 
         Note that since only SIGTERM is supported on Windows, this function is
         only useful on Unix systems.
         """
         pass
 
     @abc.abstractproperty
     def is_alive(self):
         """Is the kernel process still running?"""
         pass