explicit allow_none

IPython/core/shellapp.py

@@ -1,437 +1,437
 # encoding: utf-8
 """
 A mixin for :class:`~IPython.core.application.Application` classes that
 launch InteractiveShell instances, load extensions, etc.
 
 Authors
 -------
 
 * Min Ragan-Kelley
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2011  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
 #-----------------------------------------------------------------------------
 
 from __future__ import absolute_import
 from __future__ import print_function
 
 import glob
 import os
 import sys
 
 from IPython.config.application import boolean_flag
 from IPython.config.configurable import Configurable
 from IPython.config.loader import Config
 from IPython.core import pylabtools
 from IPython.utils import py3compat
 from IPython.utils.contexts import preserve_keys
 from IPython.utils.path import filefind
 from IPython.utils.traitlets import (
     Unicode, Instance, List, Bool, CaselessStrEnum
 )
 from IPython.lib.inputhook import guis
 
 #-----------------------------------------------------------------------------
 # Aliases and Flags
 #-----------------------------------------------------------------------------
 
 gui_keys = tuple(sorted([ key for key in guis if key is not None ]))
 
 backend_keys = sorted(pylabtools.backends.keys())
 backend_keys.insert(0, 'auto')
 
 shell_flags = {}
 
 addflag = lambda *args: shell_flags.update(boolean_flag(*args))
 addflag('autoindent', 'InteractiveShell.autoindent',
         'Turn on autoindenting.', 'Turn off autoindenting.'
 )
 addflag('automagic', 'InteractiveShell.automagic',
         """Turn on the auto calling of magic commands. Type %%magic at the
         IPython  prompt  for  more information.""",
         'Turn off the auto calling of magic commands.'
 )
 addflag('pdb', 'InteractiveShell.pdb',
     "Enable auto calling the pdb debugger after every exception.",
     "Disable auto calling the pdb debugger after every exception."
 )
 # pydb flag doesn't do any config, as core.debugger switches on import,
 # which is before parsing.  This just allows the flag to be passed.
 shell_flags.update(dict(
     pydb = ({},
         """Use the third party 'pydb' package as debugger, instead of pdb.
         Requires that pydb is installed."""
     )
 ))
 addflag('pprint', 'PlainTextFormatter.pprint',
     "Enable auto pretty printing of results.",
     "Disable auto pretty printing of results."
 )
 addflag('color-info', 'InteractiveShell.color_info',
     """IPython can display information about objects via a set of functions,
     and optionally can use colors for this, syntax highlighting
     source code and various other elements. This is on by default, but can cause
     problems with some pagers. If you see such problems, you can disable the
     colours.""",
     "Disable using colors for info related things."
 )
 addflag('deep-reload', 'InteractiveShell.deep_reload',
     """Enable deep (recursive) reloading by default. IPython can use the
     deep_reload module which reloads changes in modules recursively (it
     replaces the reload() function, so you don't need to change anything to
     use it). deep_reload() forces a full reload of modules whose code may
     have changed, which the default reload() function does not.  When
     deep_reload is off, IPython will use the normal reload(), but
     deep_reload will still be available as dreload(). This feature is off
     by default [which means that you have both normal reload() and
     dreload()].""",
     "Disable deep (recursive) reloading by default."
 )
 nosep_config = Config()
 nosep_config.InteractiveShell.separate_in = ''
 nosep_config.InteractiveShell.separate_out = ''
 nosep_config.InteractiveShell.separate_out2 = ''
 
 shell_flags['nosep']=(nosep_config, "Eliminate all spacing between prompts.")
 shell_flags['pylab'] = (
     {'InteractiveShellApp' : {'pylab' : 'auto'}},
     """Pre-load matplotlib and numpy for interactive use with
     the default matplotlib backend."""
 )
 shell_flags['matplotlib'] = (
     {'InteractiveShellApp' : {'matplotlib' : 'auto'}},
     """Configure matplotlib for interactive use with
     the default matplotlib backend."""
 )
 
 # it's possible we don't want short aliases for *all* of these:
 shell_aliases = dict(
     autocall='InteractiveShell.autocall',
     colors='InteractiveShell.colors',
     logfile='InteractiveShell.logfile',
     logappend='InteractiveShell.logappend',
     c='InteractiveShellApp.code_to_run',
     m='InteractiveShellApp.module_to_run',
     ext='InteractiveShellApp.extra_extension',
     gui='InteractiveShellApp.gui',
     pylab='InteractiveShellApp.pylab',
     matplotlib='InteractiveShellApp.matplotlib',
 )
 shell_aliases['cache-size'] = 'InteractiveShell.cache_size'
 
 #-----------------------------------------------------------------------------
 # Main classes and functions
 #-----------------------------------------------------------------------------
 
 class InteractiveShellApp(Configurable):
     """A Mixin for applications that start InteractiveShell instances.
     
     Provides configurables for loading extensions and executing files
     as part of configuring a Shell environment.
 
     The following methods should be called by the :meth:`initialize` method
     of the subclass:
 
       - :meth:`init_path`
       - :meth:`init_shell` (to be implemented by the subclass)
       - :meth:`init_gui_pylab`
       - :meth:`init_extensions`
       - :meth:`init_code`
     """
     extensions = List(Unicode, config=True,
         help="A list of dotted module names of IPython extensions to load."
     )
     extra_extension = Unicode('', config=True,
         help="dotted module name of an IPython extension to load."
     )
     def _extra_extension_changed(self, name, old, new):
         if new:
             # add to self.extensions
             self.extensions.append(new)
     
     # Extensions that are always loaded (not configurable)
     default_extensions = List(Unicode, [u'storemagic'], config=False)
     
     hide_initial_ns = Bool(True, config=True,
         help="""Should variables loaded at startup (by startup files, exec_lines, etc.)
         be hidden from tools like %who?"""
     )
 
     exec_files = List(Unicode, config=True,
         help="""List of files to run at IPython startup."""
     )
     exec_PYTHONSTARTUP = Bool(True, config=True,
         help="""Run the file referenced by the PYTHONSTARTUP environment
         variable at IPython startup."""
     )
     file_to_run = Unicode('', config=True,
         help="""A file to be run""")
 
     exec_lines = List(Unicode, config=True,
         help="""lines of code to run at IPython startup."""
     )
     code_to_run = Unicode('', config=True,
         help="Execute the given command string."
     )
     module_to_run = Unicode('', config=True,
         help="Run the module as a script."
     )
-    gui = CaselessStrEnum(gui_keys, config=True,
+    gui = CaselessStrEnum(gui_keys, config=True, allow_none=True,
         help="Enable GUI event loop integration with any of {0}.".format(gui_keys)
     )
-    matplotlib = CaselessStrEnum(backend_keys,
+    matplotlib = CaselessStrEnum(backend_keys, allow_none=True,
         config=True,
         help="""Configure matplotlib for interactive use with
         the default matplotlib backend."""
     )
-    pylab = CaselessStrEnum(backend_keys,
+    pylab = CaselessStrEnum(backend_keys, allow_none=True,
         config=True,
         help="""Pre-load matplotlib and numpy for interactive use,
         selecting a particular matplotlib backend and loop integration.
         """
     )
     pylab_import_all = Bool(True, config=True,
         help="""If true, IPython will populate the user namespace with numpy, pylab, etc.
         and an ``import *`` is done from numpy and pylab, when using pylab mode.
         
         When False, pylab mode should not import any names into the user namespace.
         """
     )
     shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
     
     user_ns = Instance(dict, args=None, allow_none=True)
     def _user_ns_changed(self, name, old, new):
         if self.shell is not None:
             self.shell.user_ns = new
             self.shell.init_user_ns()
 
     def init_path(self):
         """Add current working directory, '', to sys.path"""
         if sys.path[0] != '':
             sys.path.insert(0, '')
 
     def init_shell(self):
         raise NotImplementedError("Override in subclasses")
 
     def init_gui_pylab(self):
         """Enable GUI event loop integration, taking pylab into account."""
         enable = False
         shell = self.shell
         if self.pylab:
             enable = lambda key: shell.enable_pylab(key, import_all=self.pylab_import_all)
             key = self.pylab
         elif self.matplotlib:
             enable = shell.enable_matplotlib
             key = self.matplotlib
         elif self.gui:
             enable = shell.enable_gui
             key = self.gui
         
         if not enable:
             return
         
         try:
             r = enable(key)
         except ImportError:
             self.log.warn("Eventloop or matplotlib integration failed. Is matplotlib installed?")
             self.shell.showtraceback()
             return
         except Exception:
             self.log.warn("GUI event loop or pylab initialization failed")
             self.shell.showtraceback()
             return
             
         if isinstance(r, tuple):
             gui, backend = r[:2]
             self.log.info("Enabling GUI event loop integration, "
                       "eventloop=%s, matplotlib=%s", gui, backend)
             if key == "auto":
                 print("Using matplotlib backend: %s" % backend)
         else:
             gui = r
             self.log.info("Enabling GUI event loop integration, "
                       "eventloop=%s", gui)
 
     def init_extensions(self):
         """Load all IPython extensions in IPythonApp.extensions.
 
         This uses the :meth:`ExtensionManager.load_extensions` to load all
         the extensions listed in ``self.extensions``.
         """
         try:
             self.log.debug("Loading IPython extensions...")
             extensions = self.default_extensions + self.extensions
             for ext in extensions:
                 try:
                     self.log.info("Loading IPython extension: %s" % ext)
                     self.shell.extension_manager.load_extension(ext)
                 except:
                     msg = ("Error in loading extension: {ext}\n"
                            "Check your config files in {location}".format(
                                ext=ext,
                                location=self.profile_dir.location
                            ))
                     self.log.warn(msg, exc_info=True)
         except:
             self.log.warn("Unknown error in loading extensions:", exc_info=True)
 
     def init_code(self):
         """run the pre-flight code, specified via exec_lines"""
         self._run_startup_files()
         self._run_exec_lines()
         self._run_exec_files()
         
         # Hide variables defined here from %who etc.
         if self.hide_initial_ns:
             self.shell.user_ns_hidden.update(self.shell.user_ns)
         
         # command-line execution (ipython -i script.py, ipython -m module)
         # should *not* be excluded from %whos
         self._run_cmd_line_code()
         self._run_module()
         
         # flush output, so itwon't be attached to the first cell
         sys.stdout.flush()
         sys.stderr.flush()
 
     def _run_exec_lines(self):
         """Run lines of code in IPythonApp.exec_lines in the user's namespace."""
         if not self.exec_lines:
             return
         try:
             self.log.debug("Running code from IPythonApp.exec_lines...")
             for line in self.exec_lines:
                 try:
                     self.log.info("Running code in user namespace: %s" %
                                   line)
                     self.shell.run_cell(line, store_history=False)
                 except:
                     self.log.warn("Error in executing line in user "
                                   "namespace: %s" % line)
                     self.shell.showtraceback()
         except:
             self.log.warn("Unknown error in handling IPythonApp.exec_lines:")
             self.shell.showtraceback()
 
     def _exec_file(self, fname, shell_futures=False):
         try:
             full_filename = filefind(fname, [u'.', self.ipython_dir])
         except IOError as e:
             self.log.warn("File not found: %r"%fname)
             return
         # Make sure that the running script gets a proper sys.argv as if it
         # were run from a system shell.
         save_argv = sys.argv
         sys.argv = [full_filename] + self.extra_args[1:]
         # protect sys.argv from potential unicode strings on Python 2:
         if not py3compat.PY3:
             sys.argv = [ py3compat.cast_bytes(a) for a in sys.argv ]
         try:
             if os.path.isfile(full_filename):
                 self.log.info("Running file in user namespace: %s" %
                               full_filename)
                 # Ensure that __file__ is always defined to match Python
                 # behavior.
                 with preserve_keys(self.shell.user_ns, '__file__'):
                     self.shell.user_ns['__file__'] = fname
                     if full_filename.endswith('.ipy'):
                         self.shell.safe_execfile_ipy(full_filename,
                                                      shell_futures=shell_futures)
                     else:
                         # default to python, even without extension
                         self.shell.safe_execfile(full_filename,
                                                  self.shell.user_ns,
                                                  shell_futures=shell_futures)
         finally:
             sys.argv = save_argv
 
     def _run_startup_files(self):
         """Run files from profile startup directory"""
         startup_dir = self.profile_dir.startup_dir
         startup_files = []
         
         if self.exec_PYTHONSTARTUP and os.environ.get('PYTHONSTARTUP', False) and \
                 not (self.file_to_run or self.code_to_run or self.module_to_run):
             python_startup = os.environ['PYTHONSTARTUP']
             self.log.debug("Running PYTHONSTARTUP file %s...", python_startup)
             try:
                 self._exec_file(python_startup)
             except:
                 self.log.warn("Unknown error in handling PYTHONSTARTUP file %s:", python_startup)
                 self.shell.showtraceback()
             finally:
                 # Many PYTHONSTARTUP files set up the readline completions,
                 # but this is often at odds with IPython's own completions.
                 # Do not allow PYTHONSTARTUP to set up readline.
                 if self.shell.has_readline:
                     self.shell.set_readline_completer()
         
         startup_files += glob.glob(os.path.join(startup_dir, '*.py'))
         startup_files += glob.glob(os.path.join(startup_dir, '*.ipy'))
         if not startup_files:
             return
         
         self.log.debug("Running startup files from %s...", startup_dir)
         try:
             for fname in sorted(startup_files):
                 self._exec_file(fname)
         except:
             self.log.warn("Unknown error in handling startup files:")
             self.shell.showtraceback()
 
     def _run_exec_files(self):
         """Run files from IPythonApp.exec_files"""
         if not self.exec_files:
             return
 
         self.log.debug("Running files in IPythonApp.exec_files...")
         try:
             for fname in self.exec_files:
                 self._exec_file(fname)
         except:
             self.log.warn("Unknown error in handling IPythonApp.exec_files:")
             self.shell.showtraceback()
 
     def _run_cmd_line_code(self):
         """Run code or file specified at the command-line"""
         if self.code_to_run:
             line = self.code_to_run
             try:
                 self.log.info("Running code given at command line (c=): %s" %
                               line)
                 self.shell.run_cell(line, store_history=False)
             except:
                 self.log.warn("Error in executing line in user namespace: %s" %
                               line)
                 self.shell.showtraceback()
 
         # Like Python itself, ignore the second if the first of these is present
         elif self.file_to_run:
             fname = self.file_to_run
             try:
                 self._exec_file(fname, shell_futures=True)
             except:
                 self.log.warn("Error in executing file in user namespace: %s" %
                               fname)
                 self.shell.showtraceback()
 
     def _run_module(self):
         """Run module specified at the command-line."""
         if self.module_to_run:
             # Make sure that the module gets a proper sys.argv as if it were
             # run using `python -m`.
             save_argv = sys.argv
             sys.argv = [sys.executable] + self.extra_args
             try:
                 self.shell.safe_run_module(self.module_to_run,
                                            self.shell.user_ns)
             finally:
                 sys.argv = save_argv

IPython/kernel/tests/test_message_spec.py

@@ -1,496 +1,496
 """Test suite for our zeromq-based message specification."""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 import re
 import sys
 from distutils.version import LooseVersion as V
 try:
     from queue import Empty  # Py 3
 except ImportError:
     from Queue import Empty  # Py 2
 
 import nose.tools as nt
 
 from IPython.utils.traitlets import (
     HasTraits, TraitError, Bool, Unicode, Dict, Integer, List, Enum,
 )
 from IPython.utils.py3compat import string_types, iteritems
 
 from .utils import TIMEOUT, start_global_kernel, flush_channels, execute
 
 #-----------------------------------------------------------------------------
 # Globals
 #-----------------------------------------------------------------------------
 KC = None
 
 def setup():
     global KC
     KC = start_global_kernel()
 
 #-----------------------------------------------------------------------------
 # Message Spec References
 #-----------------------------------------------------------------------------
 
 class Reference(HasTraits):
 
     """
     Base class for message spec specification testing.
 
     This class is the core of the message specification test.  The
     idea is that child classes implement trait attributes for each
     message keys, so that message keys can be tested against these
     traits using :meth:`check` method.
 
     """
 
     def check(self, d):
         """validate a dict against our traits"""
         for key in self.trait_names():
             nt.assert_in(key, d)
             # FIXME: always allow None, probably not a good idea
             if d[key] is None:
                 continue
             try:
                 setattr(self, key, d[key])
             except TraitError as e:
                 assert False, str(e)
 
 
 class Version(Unicode):
     def __init__(self, *args, **kwargs):
         self.min = kwargs.pop('min', None)
         self.max = kwargs.pop('max', None)
         kwargs['default_value'] = self.min
         super(Version, self).__init__(*args, **kwargs)
     
     def validate(self, obj, value):
         if self.min and V(value) < V(self.min):
             raise TraitError("bad version: %s < %s" % (value, self.min))
         if self.max and (V(value) > V(self.max)):
             raise TraitError("bad version: %s > %s" % (value, self.max))
 
 
 class RMessage(Reference):
     msg_id = Unicode()
     msg_type = Unicode()
     header = Dict()
     parent_header = Dict()
     content = Dict()
     
     def check(self, d):
         super(RMessage, self).check(d)
         RHeader().check(self.header)
         if self.parent_header:
             RHeader().check(self.parent_header)
 
 class RHeader(Reference):
     msg_id = Unicode()
     msg_type = Unicode()
     session = Unicode()
     username = Unicode()
     version = Version(min='5.0')
 
 mime_pat = re.compile(r'^[\w\-\+\.]+/[\w\-\+\.]+$')
 
 class MimeBundle(Reference):
     metadata = Dict()
     data = Dict()
     def _data_changed(self, name, old, new):
         for k,v in iteritems(new):
             assert mime_pat.match(k)
             nt.assert_is_instance(v, string_types)
 
 # shell replies
 
 class ExecuteReply(Reference):
     execution_count = Integer()
-    status = Enum((u'ok', u'error'))
+    status = Enum((u'ok', u'error'), allow_none=True)
     
     def check(self, d):
         Reference.check(self, d)
         if d['status'] == 'ok':
             ExecuteReplyOkay().check(d)
         elif d['status'] == 'error':
             ExecuteReplyError().check(d)
 
 
 class ExecuteReplyOkay(Reference):
     payload = List(Dict)
     user_expressions = Dict()
 
 
 class ExecuteReplyError(Reference):
     ename = Unicode()
     evalue = Unicode()
     traceback = List(Unicode)
 
 
 class InspectReply(MimeBundle):
     found = Bool()
 
 
 class ArgSpec(Reference):
     args = List(Unicode)
     varargs = Unicode()
     varkw = Unicode()
     defaults = List()
 
 
 class Status(Reference):
-    execution_state = Enum((u'busy', u'idle', u'starting'))
+    execution_state = Enum((u'busy', u'idle', u'starting'), allow_none=True)
 
 
 class CompleteReply(Reference):
     matches = List(Unicode)
     cursor_start = Integer()
     cursor_end = Integer()
     status = Unicode()
 
 class LanguageInfo(Reference):
     name = Unicode('python')
     version = Unicode(sys.version.split()[0])
 
 class KernelInfoReply(Reference):
     protocol_version = Version(min='5.0')
     implementation = Unicode('ipython')
     implementation_version = Version(min='2.1')
     language_info = Dict()
     banner = Unicode()
     
     def check(self, d):
         Reference.check(self, d)
         LanguageInfo().check(d['language_info'])
 
 
 class IsCompleteReply(Reference):
-    status = Enum((u'complete', u'incomplete', u'invalid', u'unknown'))
+    status = Enum((u'complete', u'incomplete', u'invalid', u'unknown'), allow_none=True)
     
     def check(self, d):
         Reference.check(self, d)
         if d['status'] == 'incomplete':
             IsCompleteReplyIncomplete().check(d)
 
 class IsCompleteReplyIncomplete(Reference):
     indent = Unicode()
 
 
 # IOPub messages
 
 class ExecuteInput(Reference):
     code = Unicode()
     execution_count = Integer()
 
 
 Error = ExecuteReplyError
 
 
 class Stream(Reference):
-    name = Enum((u'stdout', u'stderr'))
+    name = Enum((u'stdout', u'stderr'), allow_none=True)
     text = Unicode()
 
 
 class DisplayData(MimeBundle):
     pass
 
 
 class ExecuteResult(MimeBundle):
     execution_count = Integer()
 
 class HistoryReply(Reference):
     history = List(List())
 
 
 references = {
     'execute_reply' : ExecuteReply(),
     'inspect_reply' : InspectReply(),
     'status' : Status(),
     'complete_reply' : CompleteReply(),
     'kernel_info_reply': KernelInfoReply(),
     'is_complete_reply': IsCompleteReply(),
     'execute_input' : ExecuteInput(),
     'execute_result' : ExecuteResult(),
     'history_reply' : HistoryReply(),
     'error' : Error(),
     'stream' : Stream(),
     'display_data' : DisplayData(),
     'header' : RHeader(),
 }
 """
 Specifications of `content` part of the reply messages.
 """
 
 
 def validate_message(msg, msg_type=None, parent=None):
     """validate a message
     
     This is a generator, and must be iterated through to actually
     trigger each test.
     
     If msg_type and/or parent are given, the msg_type and/or parent msg_id
     are compared with the given values.
     """
     RMessage().check(msg)
     if msg_type:
         nt.assert_equal(msg['msg_type'], msg_type)
     if parent:
         nt.assert_equal(msg['parent_header']['msg_id'], parent)
     content = msg['content']
     ref = references[msg['msg_type']]
     ref.check(content)
 
 
 #-----------------------------------------------------------------------------
 # Tests
 #-----------------------------------------------------------------------------
 
 # Shell channel
 
 def test_execute():
     flush_channels()
     
     msg_id = KC.execute(code='x=1')
     reply = KC.get_shell_msg(timeout=TIMEOUT)
     validate_message(reply, 'execute_reply', msg_id)
 
 
 def test_execute_silent():
     flush_channels()
     msg_id, reply = execute(code='x=1', silent=True)
     
     # flush status=idle
     status = KC.iopub_channel.get_msg(timeout=TIMEOUT)
     validate_message(status, 'status', msg_id)
     nt.assert_equal(status['content']['execution_state'], 'idle')
 
     nt.assert_raises(Empty, KC.iopub_channel.get_msg, timeout=0.1)
     count = reply['execution_count']
     
     msg_id, reply = execute(code='x=2', silent=True)
     
     # flush status=idle
     status = KC.iopub_channel.get_msg(timeout=TIMEOUT)
     validate_message(status, 'status', msg_id)
     nt.assert_equal(status['content']['execution_state'], 'idle')
     
     nt.assert_raises(Empty, KC.iopub_channel.get_msg, timeout=0.1)
     count_2 = reply['execution_count']
     nt.assert_equal(count_2, count)
 
 
 def test_execute_error():
     flush_channels()
     
     msg_id, reply = execute(code='1/0')
     nt.assert_equal(reply['status'], 'error')
     nt.assert_equal(reply['ename'], 'ZeroDivisionError')
     
     error = KC.iopub_channel.get_msg(timeout=TIMEOUT)
     validate_message(error, 'error', msg_id)
 
 
 def test_execute_inc():
     """execute request should increment execution_count"""
     flush_channels()
 
     msg_id, reply = execute(code='x=1')
     count = reply['execution_count']
     
     flush_channels()
     
     msg_id, reply = execute(code='x=2')
     count_2 = reply['execution_count']
     nt.assert_equal(count_2, count+1)
 
 def test_execute_stop_on_error():
     """execute request should not abort execution queue with stop_on_error False"""
     flush_channels()
     
     fail = '\n'.join([
         # sleep to ensure subsequent message is waiting in the queue to be aborted
         'import time',
         'time.sleep(0.5)',
         'raise ValueError',
     ])
     KC.execute(code=fail)
     msg_id = KC.execute(code='print("Hello")')
     KC.get_shell_msg(timeout=TIMEOUT)
     reply = KC.get_shell_msg(timeout=TIMEOUT)
     nt.assert_equal(reply['content']['status'], 'aborted')
 
     flush_channels()
 
     KC.execute(code=fail, stop_on_error=False)
     msg_id = KC.execute(code='print("Hello")')
     KC.get_shell_msg(timeout=TIMEOUT)
     reply = KC.get_shell_msg(timeout=TIMEOUT)
     nt.assert_equal(reply['content']['status'], 'ok')
 
 
 def test_user_expressions():
     flush_channels()
 
     msg_id, reply = execute(code='x=1', user_expressions=dict(foo='x+1'))
     user_expressions = reply['user_expressions']
     nt.assert_equal(user_expressions, {u'foo': {
         u'status': u'ok',
         u'data': {u'text/plain': u'2'},
         u'metadata': {},
     }})
 
 
 def test_user_expressions_fail():
     flush_channels()
 
     msg_id, reply = execute(code='x=0', user_expressions=dict(foo='nosuchname'))
     user_expressions = reply['user_expressions']
     foo = user_expressions['foo']
     nt.assert_equal(foo['status'], 'error')
     nt.assert_equal(foo['ename'], 'NameError')
 
 
 def test_oinfo():
     flush_channels()
 
     msg_id = KC.inspect('a')
     reply = KC.get_shell_msg(timeout=TIMEOUT)
     validate_message(reply, 'inspect_reply', msg_id)
 
 
 def test_oinfo_found():
     flush_channels()
 
     msg_id, reply = execute(code='a=5')
     
     msg_id = KC.inspect('a')
     reply = KC.get_shell_msg(timeout=TIMEOUT)
     validate_message(reply, 'inspect_reply', msg_id)
     content = reply['content']
     assert content['found']
     text = content['data']['text/plain']
     nt.assert_in('Type:', text)
     nt.assert_in('Docstring:', text)
 
 
 def test_oinfo_detail():
     flush_channels()
 
     msg_id, reply = execute(code='ip=get_ipython()')
     
     msg_id = KC.inspect('ip.object_inspect', cursor_pos=10, detail_level=1)
     reply = KC.get_shell_msg(timeout=TIMEOUT)
     validate_message(reply, 'inspect_reply', msg_id)
     content = reply['content']
     assert content['found']
     text = content['data']['text/plain']
     nt.assert_in('Definition:', text)
     nt.assert_in('Source:', text)
 
 
 def test_oinfo_not_found():
     flush_channels()
 
     msg_id = KC.inspect('dne')
     reply = KC.get_shell_msg(timeout=TIMEOUT)
     validate_message(reply, 'inspect_reply', msg_id)
     content = reply['content']
     nt.assert_false(content['found'])
 
 
 def test_complete():
     flush_channels()
 
     msg_id, reply = execute(code="alpha = albert = 5")
     
     msg_id = KC.complete('al', 2)
     reply = KC.get_shell_msg(timeout=TIMEOUT)
     validate_message(reply, 'complete_reply', msg_id)
     matches = reply['content']['matches']
     for name in ('alpha', 'albert'):
         nt.assert_in(name, matches)
 
 
 def test_kernel_info_request():
     flush_channels()
 
     msg_id = KC.kernel_info()
     reply = KC.get_shell_msg(timeout=TIMEOUT)
     validate_message(reply, 'kernel_info_reply', msg_id)
 
 
 def test_single_payload():
     flush_channels()
     msg_id, reply = execute(code="for i in range(3):\n"+
                                  "   x=range?\n")
     payload = reply['payload']
     next_input_pls = [pl for pl in payload if pl["source"] == "set_next_input"]
     nt.assert_equal(len(next_input_pls), 1)
 
 def test_is_complete():
     flush_channels()
 
     msg_id = KC.is_complete("a = 1")
     reply = KC.get_shell_msg(timeout=TIMEOUT)
     validate_message(reply, 'is_complete_reply', msg_id)
 
 def test_history_range():
     flush_channels()
     
     msg_id_exec = KC.execute(code='x=1', store_history = True)
     reply_exec = KC.get_shell_msg(timeout=TIMEOUT)
     
     msg_id = KC.history(hist_access_type = 'range', raw = True, output = True, start = 1, stop = 2, session = 0)
     reply = KC.get_shell_msg(timeout=TIMEOUT)
     validate_message(reply, 'history_reply', msg_id)
     content = reply['content']
     nt.assert_equal(len(content['history']), 1)
 
 def test_history_tail():
     flush_channels()
     
     msg_id_exec = KC.execute(code='x=1', store_history = True)
     reply_exec = KC.get_shell_msg(timeout=TIMEOUT)
     
     msg_id = KC.history(hist_access_type = 'tail', raw = True, output = True, n = 1, session = 0)
     reply = KC.get_shell_msg(timeout=TIMEOUT)
     validate_message(reply, 'history_reply', msg_id)
     content = reply['content']
     nt.assert_equal(len(content['history']), 1)
 
 def test_history_search():
     flush_channels()
     
     msg_id_exec = KC.execute(code='x=1', store_history = True)
     reply_exec = KC.get_shell_msg(timeout=TIMEOUT)
     
     msg_id = KC.history(hist_access_type = 'search', raw = True, output = True, n = 1, pattern = '*', session = 0)
     reply = KC.get_shell_msg(timeout=TIMEOUT)
     validate_message(reply, 'history_reply', msg_id)
     content = reply['content']
     nt.assert_equal(len(content['history']), 1)
 
 # IOPub channel
 
 
 def test_stream():
     flush_channels()
 
     msg_id, reply = execute("print('hi')")
 
     stdout = KC.iopub_channel.get_msg(timeout=TIMEOUT)
     validate_message(stdout, 'stream', msg_id)
     content = stdout['content']
     nt.assert_equal(content['text'], u'hi\n')
 
 
 def test_display_data():
     flush_channels()
 
     msg_id, reply = execute("from IPython.core.display import display; display(1)")
     
     display = KC.iopub_channel.get_msg(timeout=TIMEOUT)
     validate_message(display, 'display_data', parent=msg_id)
     data = display['content']['data']
     nt.assert_equal(data['text/plain'], u'1')
 

IPython/terminal/console/interactiveshell.py

@@ -1,578 +1,578
 # -*- coding: utf-8 -*-
 """terminal client to the IPython kernel"""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 from __future__ import print_function
 
 import base64
 import bdb
 import signal
 import os
 import sys
 import time
 import subprocess
 from getpass import getpass
 from io import BytesIO
 
 try:
     from queue import Empty  # Py 3
 except ImportError:
     from Queue import Empty  # Py 2
 
 from IPython.core import page
 from IPython.core import release
 from IPython.terminal.console.zmqhistory import ZMQHistoryManager
 from IPython.utils.warn import warn, error
 from IPython.utils import io
 from IPython.utils.py3compat import string_types, input
 from IPython.utils.traitlets import List, Enum, Any, Instance, Unicode, Float, Bool
 from IPython.utils.tempdir import NamedFileInTemporaryDirectory
 
 from IPython.terminal.interactiveshell import TerminalInteractiveShell
 from IPython.terminal.console.completer import ZMQCompleter
 
 class ZMQTerminalInteractiveShell(TerminalInteractiveShell):
     """A subclass of TerminalInteractiveShell that uses the 0MQ kernel"""
     _executing = False
     _execution_state = Unicode('')
     _pending_clearoutput = False
     kernel_banner = Unicode('')
     kernel_timeout = Float(60, config=True,
         help="""Timeout for giving up on a kernel (in seconds).
         
         On first connect and restart, the console tests whether the
         kernel is running and responsive by sending kernel_info_requests.
         This sets the timeout in seconds for how long the kernel can take
         before being presumed dead.
         """
     )
 
     image_handler = Enum(('PIL', 'stream', 'tempfile', 'callable'),
-                         config=True, help=
+                         config=True, allow_none=True, help=
         """
         Handler for image type output.  This is useful, for example,
         when connecting to the kernel in which pylab inline backend is
         activated.  There are four handlers defined.  'PIL': Use
         Python Imaging Library to popup image; 'stream': Use an
         external program to show the image.  Image will be fed into
         the STDIN of the program.  You will need to configure
         `stream_image_handler`; 'tempfile': Use an external program to
         show the image.  Image will be saved in a temporally file and
         the program is called with the temporally file.  You will need
         to configure `tempfile_image_handler`; 'callable': You can set
         any Python callable which is called with the image data.  You
         will need to configure `callable_image_handler`.
         """
     )
 
     stream_image_handler = List(config=True, help=
         """
         Command to invoke an image viewer program when you are using
         'stream' image handler.  This option is a list of string where
         the first element is the command itself and reminders are the
         options for the command.  Raw image data is given as STDIN to
         the program.
         """
     )
 
     tempfile_image_handler = List(config=True, help=
         """
         Command to invoke an image viewer program when you are using
         'tempfile' image handler.  This option is a list of string
         where the first element is the command itself and reminders
         are the options for the command.  You can use {file} and
         {format} in the string to represent the location of the
         generated image file and image format.
         """
     )
 
     callable_image_handler = Any(config=True, help=
         """
         Callable object called via 'callable' image handler with one
         argument, `data`, which is `msg["content"]["data"]` where
         `msg` is the message from iopub channel.  For exmaple, you can
         find base64 encoded PNG data as `data['image/png']`.
         """
     )
 
     mime_preference = List(
         default_value=['image/png', 'image/jpeg', 'image/svg+xml'],
         config=True, allow_none=False, help=
         """
         Preferred object representation MIME type in order.  First
         matched MIME type will be used.
         """
     )
 
     manager = Instance('IPython.kernel.KernelManager')
     client = Instance('IPython.kernel.KernelClient')
     def _client_changed(self, name, old, new):
         self.session_id = new.session.session
     session_id = Unicode()
 
     def init_completer(self):
         """Initialize the completion machinery.
 
         This creates completion machinery that can be used by client code,
         either interactively in-process (typically triggered by the readline
         library), programmatically (such as in test suites) or out-of-process
         (typically over the network by remote frontends).
         """
         from IPython.core.completerlib import (module_completer,
                                                magic_run_completer, cd_completer)
         
         self.Completer = ZMQCompleter(self, self.client, config=self.config)
         
 
         self.set_hook('complete_command', module_completer, str_key = 'import')
         self.set_hook('complete_command', module_completer, str_key = 'from')
         self.set_hook('complete_command', magic_run_completer, str_key = '%run')
         self.set_hook('complete_command', cd_completer, str_key = '%cd')
 
         # Only configure readline if we truly are using readline.  IPython can
         # do tab-completion over the network, in GUIs, etc, where readline
         # itself may be absent
         if self.has_readline:
             self.set_readline_completer()
     
     def run_cell(self, cell, store_history=True):
         """Run a complete IPython cell.
         
         Parameters
         ----------
         cell : str
           The code (including IPython code such as %magic functions) to run.
         store_history : bool
           If True, the raw and translated cell will be stored in IPython's
           history. For user code calling back into IPython's machinery, this
           should be set to False.
         """
         if (not cell) or cell.isspace():
             # pressing enter flushes any pending display
             self.handle_iopub()
             return
         
         # flush stale replies, which could have been ignored, due to missed heartbeats
         while self.client.shell_channel.msg_ready():
             self.client.shell_channel.get_msg()
         # execute takes 'hidden', which is the inverse of store_hist
         msg_id = self.client.execute(cell, not store_history)
         
         # first thing is wait for any side effects (output, stdin, etc.)
         self._executing = True
         self._execution_state = "busy"
         while self._execution_state != 'idle' and self.client.is_alive():
             try:
                 self.handle_input_request(msg_id, timeout=0.05)
             except Empty:
                 # display intermediate print statements, etc.
                 self.handle_iopub(msg_id)
         
         # after all of that is done, wait for the execute reply
         while self.client.is_alive():
             try:
                 self.handle_execute_reply(msg_id, timeout=0.05)
             except Empty:
                 pass
             else:
                 break
         self._executing = False
 
     #-----------------
     # message handlers
     #-----------------
 
     def handle_execute_reply(self, msg_id, timeout=None):
         msg = self.client.shell_channel.get_msg(block=False, timeout=timeout)
         if msg["parent_header"].get("msg_id", None) == msg_id:
             
             self.handle_iopub(msg_id)
             
             content = msg["content"]
             status = content['status']
             
             if status == 'aborted':
                 self.write('Aborted\n')
                 return
             elif status == 'ok':
                 # handle payloads
                 for item in content["payload"]:
                     source = item['source']
                     if source == 'page':
                         page.page(item['data']['text/plain'])
                     elif source == 'set_next_input':
                         self.set_next_input(item['text'])
                     elif source == 'ask_exit':
                         self.ask_exit()
                
             elif status == 'error':
                 for frame in content["traceback"]:
                     print(frame, file=io.stderr)
             
             self.execution_count = int(content["execution_count"] + 1)
     
     include_other_output = Bool(False, config=True,
         help="""Whether to include output from clients
         other than this one sharing the same kernel.
         
         Outputs are not displayed until enter is pressed.
         """
     )
     other_output_prefix = Unicode("[remote] ", config=True,
         help="""Prefix to add to outputs coming from clients other than this one.
         
         Only relevant if include_other_output is True.
         """
     )
     
     def from_here(self, msg):
         """Return whether a message is from this session"""
         return msg['parent_header'].get("session", self.session_id) == self.session_id
     
     def include_output(self, msg):
         """Return whether we should include a given output message"""
         from_here = self.from_here(msg)
         if msg['msg_type'] == 'execute_input':
             # only echo inputs not from here
             return self.include_other_output and not from_here
         
         if self.include_other_output:
             return True
         else:
             return from_here
     
     def handle_iopub(self, msg_id=''):
         """Process messages on the IOPub channel
 
            This method consumes and processes messages on the IOPub channel,
            such as stdout, stderr, execute_result and status.
            
            It only displays output that is caused by this session.
         """
         while self.client.iopub_channel.msg_ready():
             sub_msg = self.client.iopub_channel.get_msg()
             msg_type = sub_msg['header']['msg_type']
             parent = sub_msg["parent_header"]
             
             if self.include_output(sub_msg):
                 if msg_type == 'status':
                     self._execution_state = sub_msg["content"]["execution_state"]
                 elif msg_type == 'stream':
                     if sub_msg["content"]["name"] == "stdout":
                         if self._pending_clearoutput:
                             print("\r", file=io.stdout, end="")
                             self._pending_clearoutput = False
                         print(sub_msg["content"]["text"], file=io.stdout, end="")
                         io.stdout.flush()
                     elif sub_msg["content"]["name"] == "stderr":
                         if self._pending_clearoutput:
                             print("\r", file=io.stderr, end="")
                             self._pending_clearoutput = False
                         print(sub_msg["content"]["text"], file=io.stderr, end="")
                         io.stderr.flush()
 
                 elif msg_type == 'execute_result':
                     if self._pending_clearoutput:
                         print("\r", file=io.stdout, end="")
                         self._pending_clearoutput = False
                     self.execution_count = int(sub_msg["content"]["execution_count"])
                     if not self.from_here(sub_msg):
                         sys.stdout.write(self.other_output_prefix)
                     format_dict = sub_msg["content"]["data"]
                     self.handle_rich_data(format_dict)
                     
                     # taken from DisplayHook.__call__:
                     hook = self.displayhook
                     hook.start_displayhook()
                     hook.write_output_prompt()
                     hook.write_format_data(format_dict)
                     hook.log_output(format_dict)
                     hook.finish_displayhook()
 
                 elif msg_type == 'display_data':
                     data = sub_msg["content"]["data"]
                     handled = self.handle_rich_data(data)
                     if not handled:
                         if not self.from_here(sub_msg):
                             sys.stdout.write(self.other_output_prefix)
                         # if it was an image, we handled it by now
                         if 'text/plain' in data:
                             print(data['text/plain'])
                 
                 elif msg_type == 'execute_input':
                     content = sub_msg['content']
                     self.execution_count = content['execution_count']
                     if not self.from_here(sub_msg):
                         sys.stdout.write(self.other_output_prefix)
                     sys.stdout.write(self.prompt_manager.render('in'))
                     sys.stdout.write(content['code'])
                 
                 elif msg_type == 'clear_output':
                     if sub_msg["content"]["wait"]:
                         self._pending_clearoutput = True
                     else:
                         print("\r", file=io.stdout, end="")
 
     _imagemime = {
         'image/png': 'png',
         'image/jpeg': 'jpeg',
         'image/svg+xml': 'svg',
     }
 
     def handle_rich_data(self, data):
         for mime in self.mime_preference:
             if mime in data and mime in self._imagemime:
                 self.handle_image(data, mime)
                 return True
 
     def handle_image(self, data, mime):
         handler = getattr(
             self, 'handle_image_{0}'.format(self.image_handler), None)
         if handler:
             handler(data, mime)
 
     def handle_image_PIL(self, data, mime):
         if mime not in ('image/png', 'image/jpeg'):
             return
         import PIL.Image
         raw = base64.decodestring(data[mime].encode('ascii'))
         img = PIL.Image.open(BytesIO(raw))
         img.show()
 
     def handle_image_stream(self, data, mime):
         raw = base64.decodestring(data[mime].encode('ascii'))
         imageformat = self._imagemime[mime]
         fmt = dict(format=imageformat)
         args = [s.format(**fmt) for s in self.stream_image_handler]
         with open(os.devnull, 'w') as devnull:
             proc = subprocess.Popen(
                 args, stdin=subprocess.PIPE,
                 stdout=devnull, stderr=devnull)
             proc.communicate(raw)
 
     def handle_image_tempfile(self, data, mime):
         raw = base64.decodestring(data[mime].encode('ascii'))
         imageformat = self._imagemime[mime]
         filename = 'tmp.{0}'.format(imageformat)
         with NamedFileInTemporaryDirectory(filename) as f, \
                     open(os.devnull, 'w') as devnull:
             f.write(raw)
             f.flush()
             fmt = dict(file=f.name, format=imageformat)
             args = [s.format(**fmt) for s in self.tempfile_image_handler]
             subprocess.call(args, stdout=devnull, stderr=devnull)
 
     def handle_image_callable(self, data, mime):
         self.callable_image_handler(data)
 
     def handle_input_request(self, msg_id, timeout=0.1):
         """ Method to capture raw_input
         """
         req = self.client.stdin_channel.get_msg(timeout=timeout)
         # in case any iopub came while we were waiting:
         self.handle_iopub(msg_id)
         if msg_id == req["parent_header"].get("msg_id"):
             # wrap SIGINT handler
             real_handler = signal.getsignal(signal.SIGINT)
             def double_int(sig,frame):
                 # call real handler (forwards sigint to kernel),
                 # then raise local interrupt, stopping local raw_input
                 real_handler(sig,frame)
                 raise KeyboardInterrupt
             signal.signal(signal.SIGINT, double_int)
             content = req['content']
             read = getpass if content.get('password', False) else input
             try:
                 raw_data = read(content["prompt"])
             except EOFError:
                 # turn EOFError into EOF character
                 raw_data = '\x04'
             except KeyboardInterrupt:
                 sys.stdout.write('\n')
                 return
             finally:
                 # restore SIGINT handler
                 signal.signal(signal.SIGINT, real_handler)
             
             # only send stdin reply if there *was not* another request
             # or execution finished while we were reading.
             if not (self.client.stdin_channel.msg_ready() or self.client.shell_channel.msg_ready()):
                 self.client.input(raw_data)
 
     def mainloop(self, display_banner=False):
         while True:
             try:
                 self.interact(display_banner=display_banner)
                 #self.interact_with_readline()
                 # XXX for testing of a readline-decoupled repl loop, call
                 # interact_with_readline above
                 break
             except KeyboardInterrupt:
                 # this should not be necessary, but KeyboardInterrupt
                 # handling seems rather unpredictable...
                 self.write("\nKeyboardInterrupt in interact()\n")
 
         self.client.shutdown()
     
     def _banner1_default(self):
         return "IPython Console {version}\n".format(version=release.version)
     
     def compute_banner(self):
         super(ZMQTerminalInteractiveShell, self).compute_banner()
         if self.client and not self.kernel_banner:
             msg_id = self.client.kernel_info()
             while True:
                 try:
                     reply = self.client.get_shell_msg(timeout=1)
                 except Empty:
                     break
                 else:
                     if reply['parent_header'].get('msg_id') == msg_id:
                         self.kernel_banner = reply['content'].get('banner', '')
                         break
         self.banner += self.kernel_banner
     
     def wait_for_kernel(self, timeout=None):
         """method to wait for a kernel to be ready"""
         tic = time.time()
         self.client.hb_channel.unpause()
         while True:
             msg_id = self.client.kernel_info()
             reply = None
             while True:
                 try:
                     reply = self.client.get_shell_msg(timeout=1)
                 except Empty:
                     break
                 else:
                     if reply['parent_header'].get('msg_id') == msg_id:
                         return True
             if timeout is not None \
                 and (time.time() - tic) > timeout \
                 and not self.client.hb_channel.is_beating():
                 # heart failed
                 return False
         return True
     
     def interact(self, display_banner=None):
         """Closely emulate the interactive Python console."""
 
         # batch run -> do not interact
         if self.exit_now:
             return
 
         if display_banner is None:
             display_banner = self.display_banner
         
         if isinstance(display_banner, string_types):
             self.show_banner(display_banner)
         elif display_banner:
             self.show_banner()
 
         more = False
         
         # run a non-empty no-op, so that we don't get a prompt until
         # we know the kernel is ready. This keeps the connection
         # message above the first prompt.
         if not self.wait_for_kernel(self.kernel_timeout):
             error("Kernel did not respond\n")
             return
         
         if self.has_readline:
             self.readline_startup_hook(self.pre_readline)
             hlen_b4_cell = self.readline.get_current_history_length()
         else:
             hlen_b4_cell = 0
         # exit_now is set by a call to %Exit or %Quit, through the
         # ask_exit callback.
 
         while not self.exit_now:
             if not self.client.is_alive():
                 # kernel died, prompt for action or exit
 
                 action = "restart" if self.manager else "wait for restart"
                 ans = self.ask_yes_no("kernel died, %s ([y]/n)?" % action, default='y')
                 if ans:
                     if self.manager:
                         self.manager.restart_kernel(True)
                     self.wait_for_kernel(self.kernel_timeout)
                 else:
                     self.exit_now = True
                 continue
             try:
                 # protect prompt block from KeyboardInterrupt
                 # when sitting on ctrl-C
                 self.hooks.pre_prompt_hook()
                 if more:
                     try:
                         prompt = self.prompt_manager.render('in2')
                     except Exception:
                         self.showtraceback()
                     if self.autoindent:
                         self.rl_do_indent = True
                     
                 else:
                     try:
                         prompt = self.separate_in + self.prompt_manager.render('in')
                     except Exception:
                         self.showtraceback()
                 
                 line = self.raw_input(prompt)
                 if self.exit_now:
                     # quick exit on sys.std[in|out] close
                     break
                 if self.autoindent:
                     self.rl_do_indent = False
                     
             except KeyboardInterrupt:
                 #double-guard against keyboardinterrupts during kbdint handling
                 try:
                     self.write('\n' + self.get_exception_only())
                     source_raw = self.input_splitter.raw_reset()
                     hlen_b4_cell = self._replace_rlhist_multiline(source_raw, hlen_b4_cell)
                     more = False
                 except KeyboardInterrupt:
                     pass
             except EOFError:
                 if self.autoindent:
                     self.rl_do_indent = False
                     if self.has_readline:
                         self.readline_startup_hook(None)
                 self.write('\n')
                 self.exit()
             except bdb.BdbQuit:
                 warn('The Python debugger has exited with a BdbQuit exception.\n'
                      'Because of how pdb handles the stack, it is impossible\n'
                      'for IPython to properly format this particular exception.\n'
                      'IPython will resume normal operation.')
             except:
                 # exceptions here are VERY RARE, but they can be triggered
                 # asynchronously by signal handlers, for example.
                 self.showtraceback()
             else:
                 try:
                     self.input_splitter.push(line)
                     more = self.input_splitter.push_accepts_more()
                 except SyntaxError:
                     # Run the code directly - run_cell takes care of displaying
                     # the exception.
                     more = False
                 if (self.SyntaxTB.last_syntax_error and
                     self.autoedit_syntax):
                     self.edit_syntax_error()
                 if not more:
                     source_raw = self.input_splitter.raw_reset()
                     hlen_b4_cell = self._replace_rlhist_multiline(source_raw, hlen_b4_cell)
                     self.run_cell(source_raw)
                 
 
         # Turn off the exit flag, so the mainloop can be restarted if desired
         self.exit_now = False
 
     def init_history(self):
         """Sets up the command history. """
         self.history_manager = ZMQHistoryManager(client=self.client) 
         self.configurables.append(self.history_manager)