Use `backcall` and introduce `ExecutionRequest`

IPython/core/events.py

@@ -1,189 +1,181 b''
 """Infrastructure for registering and firing callbacks on application events.
 
 Unlike :mod:`IPython.core.hooks`, which lets end users set single functions to
 be called at specific times, or a collection of alternative methods to try,
 callbacks are designed to be used by extension authors. A number of callbacks
 can be registered for the same event without needing to be aware of one another.
 
 The functions defined in this module are no-ops indicating the names of available
 events and the arguments which will be passed to them.
 
 .. note::
 
    This API is experimental in IPython 2.0, and may be revised in future versions.
 """
 
-from functools import wraps
-from inspect import isfunction
-try:
-    from inspect import getfullargspec
-except:
-    from inspect import getargspec as getfullargspec  # for Python2 compatibility.
-
-# original function -> wrapper function mapping
-compatibility_wrapper_functions = {}
-
-def _compatibility_wrapper_for(function):
-    """Returns a wrapper for a function without args that accepts any args."""
-    if len(getfullargspec(function).args) > 0:
-        raise TypeError('%s cannot have arguments' % function)
-    if function in compatibility_wrapper_functions:
-        return compatibility_wrapper_functions[function]
-    @wraps(function)
-    def wrapper(*args, **kwargs):
-        function()
-    compatibility_wrapper_functions[function] = wrapper
-    return wrapper
+from backcall import callback_prototype
+
 
 class EventManager(object):
     """Manage a collection of events and a sequence of callbacks for each.
     
     This is attached to :class:`~IPython.core.interactiveshell.InteractiveShell`
     instances as an ``events`` attribute.
     
     .. note::
 
        This API is experimental in IPython 2.0, and may be revised in future versions.
     """
     def __init__(self, shell, available_events):
         """Initialise the :class:`CallbackManager`.
         
         Parameters
         ----------
         shell
           The :class:`~IPython.core.interactiveshell.InteractiveShell` instance
         available_callbacks
           An iterable of names for callback events.
         """
         self.shell = shell
         self.callbacks = {n:[] for n in available_events}
     
     def register(self, event, function):
         """Register a new event callback
         
         Parameters
         ----------
         event : str
           The event for which to register this callback.
         function : callable
           A function to be called on the given event. It should take the same
           parameters as the appropriate callback prototype.
         
         Raises
         ------
         TypeError
           If ``function`` is not callable.
         KeyError
           If ``event`` is not one of the known events.
         """
         if not callable(function):
             raise TypeError('Need a callable, got %r' % function)
-
-        callback_proto = available_events.get(event)
-        if (isfunction(callback_proto) and isfunction(function) and
-            len(getfullargspec(callback_proto).args) > 0 and
-            len(getfullargspec(function).args) == 0):
-            # `callback_proto` has args but `function` does not, so a
-            # compatibility wrapper is needed.
-            self.callbacks[event].append(_compatibility_wrapper_for(function))
-        else:
-            self.callbacks[event].append(function)
+        self.callbacks[event].append(_adapt_function(event, function))
     
     def unregister(self, event, function):
         """Remove a callback from the given event."""
-        wrapper = compatibility_wrapper_functions.get(function)
-        if wrapper:
-            self.callbacks[event].remove(wrapper)
-        else:
-            self.callbacks[event].remove(function)
+        self.callbacks[event].remove(_adapt_function(event, function))
     
     def trigger(self, event, *args, **kwargs):
         """Call callbacks for ``event``.
         
         Any additional arguments are passed to all callbacks registered for this
         event. Exceptions raised by callbacks are caught, and a message printed.
         """
         for func in self.callbacks[event][:]:
             try:
                 func(*args, **kwargs)
             except Exception:
                 print("Error in callback {} (for {}):".format(func, event))
                 self.shell.showtraceback()
 
 # event_name -> prototype mapping
 available_events = {}
 
+# (event, function) -> adapted function mapping
+adapted_functions = {}
+
+
 def _define_event(callback_proto):
     available_events[callback_proto.__name__] = callback_proto
     return callback_proto
 
+
+def _adapt_function(event, function):
+    """Adapts and caches a function using `backcall` to provide compatibility.
+    
+    Function adaptations depend not only on the function but also on the event,
+    as events may expect different arguments (e.g. `request` vs. `result`).
+    Hence, `(event, function)` is used as the cache key.
+    """
+    if (event, function) in adapted_functions:
+        return adapted_functions[(event, function)]
+    callback_proto = available_events.get(event)
+    adapted_function = callback_proto.adapt(function)
+    adapted_functions[(event, function)] = adapted_function
+    return adapted_function
+
+
 # ------------------------------------------------------------------------------
 # Callback prototypes
 #
 # No-op functions which describe the names of available events and the
 # signatures of callbacks for those events.
 # ------------------------------------------------------------------------------
 
 @_define_event
-def pre_execute(result):
+@callback_prototype
+def pre_execute(request):
     """Fires before code is executed in response to user/frontend action.
     
     This includes comm and widget messages and silent execution, as well as user
     code cells.
 
     Parameters
     ----------
-    result : :class:`~IPython.core.interactiveshell.ExecutionResult`
-      The object which will be returned as the execution result.
+    request : :class:`~IPython.core.interactiveshell.ExecutionRequest`
+      The object representing the code execution request.
     """
     pass
 
 @_define_event
-def pre_run_cell(result):
+@callback_prototype
+def pre_run_cell(request):
     """Fires before user-entered code runs.
 
     Parameters
     ----------
-    result : :class:`~IPython.core.interactiveshell.ExecutionResult`
-      The object which will be returned as the execution result.
+    request : :class:`~IPython.core.interactiveshell.ExecutionRequest`
+      The object representing the code execution request.
     """
     pass
 
 @_define_event
+@callback_prototype
 def post_execute(result):
     """Fires after code is executed in response to user/frontend action.
     
     This includes comm and widget messages and silent execution, as well as user
     code cells.
 
     Parameters
     ----------
     result : :class:`~IPython.core.interactiveshell.ExecutionResult`
       The object which will be returned as the execution result.
     """
     pass
 
 @_define_event
+@callback_prototype
 def post_run_cell(result):
     """Fires after user-entered code runs.
 
     Parameters
     ----------
     result : :class:`~IPython.core.interactiveshell.ExecutionResult`
       The object which will be returned as the execution result.
     """
     pass
 
 @_define_event
 def shell_initialized(ip):
     """Fires after initialisation of :class:`~IPython.core.interactiveshell.InteractiveShell`.
     
     This is before extensions and startup scripts are loaded, so it can only be
     set by subclassing.
     
     Parameters
     ----------
     ip : :class:`~IPython.core.interactiveshell.InteractiveShell`
       The newly initialised shell.
     """
     pass

IPython/core/tests/test_events.py

@@ -1,69 +1,75 b''
+from backcall import callback_prototype
 import unittest
 from unittest.mock import Mock
 
 from IPython.core import events
 import IPython.testing.tools as tt
 
+
 @events._define_event
+@callback_prototype
 def ping_received():
     pass
 
+
 @events._define_event
+@callback_prototype
 def event_with_argument(argument):
     pass
 
+
 class CallbackTests(unittest.TestCase):
     def setUp(self):
         self.em = events.EventManager(get_ipython(), {'ping_received': ping_received, 'event_with_argument': event_with_argument})
     
     def test_register_unregister(self):
         cb = Mock()
 
         self.em.register('ping_received', cb)        
         self.em.trigger('ping_received')
         self.assertEqual(cb.call_count, 1)
         
         self.em.unregister('ping_received', cb)
         self.em.trigger('ping_received')
         self.assertEqual(cb.call_count, 1)
     
     def test_cb_error(self):
         cb = Mock(side_effect=ValueError)
         self.em.register('ping_received', cb)
         with tt.AssertPrints("Error in callback"):
             self.em.trigger('ping_received')
 
     def test_unregister_during_callback(self):
         invoked = [False] * 3
         
         def func1(*_):
             invoked[0] = True
             self.em.unregister('ping_received', func1)
             self.em.register('ping_received', func3)
 
         def func2(*_):
             invoked[1] = True
             self.em.unregister('ping_received', func2)
 
         def func3(*_):
             invoked[2] = True
             
         self.em.register('ping_received', func1)
         self.em.register('ping_received', func2)
 
         self.em.trigger('ping_received')
         self.assertEqual([True, True, False], invoked)
         self.assertEqual([func3], self.em.callbacks['ping_received'])
     
     def test_ignore_event_arguments_if_no_argument_required(self):
         call_count = [0]
         def event_with_no_argument():
             call_count[0] += 1
 
-        self.em.register('event_with_argument', event_with_no_argument)        
+        self.em.register('event_with_argument', event_with_no_argument)
         self.em.trigger('event_with_argument', 'the argument')
         self.assertEqual(call_count[0], 1)
         
         self.em.unregister('event_with_argument', event_with_no_argument)
         self.em.trigger('ping_received')
         self.assertEqual(call_count[0], 1)

IPython/core/tests/test_interactiveshell.py

@@ -1,920 +1,926 b''
 # -*- coding: utf-8 -*-
 """Tests for the key interactiveshell module.
 
 Historically the main classes in interactiveshell have been under-tested.  This
 module should grow as many single-method tests as possible to trap many of the
 recurring bugs we seem to encounter with high-level interaction.
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 import ast
 import os
 import signal
 import shutil
 import sys
 import tempfile
 import unittest
 from unittest import mock
 from io import StringIO
 
 from os.path import join
 
 import nose.tools as nt
 
 from IPython.core.error import InputRejected
 from IPython.core.inputtransformer import InputTransformer
 from IPython.testing.decorators import (
     skipif, skip_win32, onlyif_unicode_paths, onlyif_cmds_exist,
 )
 from IPython.testing import tools as tt
 from IPython.utils.process import find_cmd
 from IPython.utils import py3compat
 
 #-----------------------------------------------------------------------------
 # Globals
 #-----------------------------------------------------------------------------
 # This is used by every single test, no point repeating it ad nauseam
 ip = get_ipython()
 
 #-----------------------------------------------------------------------------
 # Tests
 #-----------------------------------------------------------------------------
 
 class DerivedInterrupt(KeyboardInterrupt):
     pass
 
 class InteractiveShellTestCase(unittest.TestCase):
     def test_naked_string_cells(self):
         """Test that cells with only naked strings are fully executed"""
         # First, single-line inputs
         ip.run_cell('"a"\n')
         self.assertEqual(ip.user_ns['_'], 'a')
         # And also multi-line cells
         ip.run_cell('"""a\nb"""\n')
         self.assertEqual(ip.user_ns['_'], 'a\nb')
 
     def test_run_empty_cell(self):
         """Just make sure we don't get a horrible error with a blank
         cell of input. Yes, I did overlook that."""
         old_xc = ip.execution_count
         res = ip.run_cell('')
         self.assertEqual(ip.execution_count, old_xc)
         self.assertEqual(res.execution_count, None)
 
     def test_run_cell_multiline(self):
         """Multi-block, multi-line cells must execute correctly.
         """
         src = '\n'.join(["x=1",
                          "y=2",
                          "if 1:",
                          "    x += 1",
                          "    y += 1",])
         res = ip.run_cell(src)
         self.assertEqual(ip.user_ns['x'], 2)
         self.assertEqual(ip.user_ns['y'], 3)
         self.assertEqual(res.success, True)
         self.assertEqual(res.result, None)
 
     def test_multiline_string_cells(self):
         "Code sprinkled with multiline strings should execute (GH-306)"
         ip.run_cell('tmp=0')
         self.assertEqual(ip.user_ns['tmp'], 0)
         res = ip.run_cell('tmp=1;"""a\nb"""\n')
         self.assertEqual(ip.user_ns['tmp'], 1)
         self.assertEqual(res.success, True)
         self.assertEqual(res.result, "a\nb")
 
     def test_dont_cache_with_semicolon(self):
         "Ending a line with semicolon should not cache the returned object (GH-307)"
         oldlen = len(ip.user_ns['Out'])
         for cell in ['1;', '1;1;']:
             res = ip.run_cell(cell, store_history=True)
             newlen = len(ip.user_ns['Out'])
             self.assertEqual(oldlen, newlen)
             self.assertIsNone(res.result)
         i = 0
         #also test the default caching behavior
         for cell in ['1', '1;1']:
             ip.run_cell(cell, store_history=True)
             newlen = len(ip.user_ns['Out'])
             i += 1
             self.assertEqual(oldlen+i, newlen)
 
     def test_syntax_error(self):
         res = ip.run_cell("raise = 3")
         self.assertIsInstance(res.error_before_exec, SyntaxError)
 
     def test_In_variable(self):
         "Verify that In variable grows with user input (GH-284)"
         oldlen = len(ip.user_ns['In'])
         ip.run_cell('1;', store_history=True)
         newlen = len(ip.user_ns['In'])
         self.assertEqual(oldlen+1, newlen)
         self.assertEqual(ip.user_ns['In'][-1],'1;')
         
     def test_magic_names_in_string(self):
         ip.run_cell('a = """\n%exit\n"""')
         self.assertEqual(ip.user_ns['a'], '\n%exit\n')
     
     def test_trailing_newline(self):
         """test that running !(command) does not raise a SyntaxError"""
         ip.run_cell('!(true)\n', False)
         ip.run_cell('!(true)\n\n\n', False)
     
     def test_gh_597(self):
         """Pretty-printing lists of objects with non-ascii reprs may cause
         problems."""
         class Spam(object):
           def __repr__(self):
             return "\xe9"*50
         import IPython.core.formatters
         f = IPython.core.formatters.PlainTextFormatter()
         f([Spam(),Spam()])
     
 
     def test_future_flags(self):
         """Check that future flags are used for parsing code (gh-777)"""
         ip.run_cell('from __future__ import barry_as_FLUFL')
         try:
             ip.run_cell('prfunc_return_val = 1 <> 2')
             assert 'prfunc_return_val' in ip.user_ns
         finally:
             # Reset compiler flags so we don't mess up other tests.
             ip.compile.reset_compiler_flags()
 
     def test_can_pickle(self):
         "Can we pickle objects defined interactively (GH-29)"
         ip = get_ipython()
         ip.reset()
         ip.run_cell(("class Mylist(list):\n"
                      "    def __init__(self,x=[]):\n"
                      "        list.__init__(self,x)"))
         ip.run_cell("w=Mylist([1,2,3])")
         
         from pickle import dumps
         
         # We need to swap in our main module - this is only necessary
         # inside the test framework, because IPython puts the interactive module
         # in place (but the test framework undoes this).
         _main = sys.modules['__main__']
         sys.modules['__main__'] = ip.user_module
         try:
             res = dumps(ip.user_ns["w"])
         finally:
             sys.modules['__main__'] = _main
         self.assertTrue(isinstance(res, bytes))
         
     def test_global_ns(self):
         "Code in functions must be able to access variables outside them."
         ip = get_ipython()
         ip.run_cell("a = 10")
         ip.run_cell(("def f(x):\n"
                      "    return x + a"))
         ip.run_cell("b = f(12)")
         self.assertEqual(ip.user_ns["b"], 22)
 
     def test_bad_custom_tb(self):
         """Check that InteractiveShell is protected from bad custom exception handlers"""
         ip.set_custom_exc((IOError,), lambda etype,value,tb: 1/0)
         self.assertEqual(ip.custom_exceptions, (IOError,))
         with tt.AssertPrints("Custom TB Handler failed", channel='stderr'):
             ip.run_cell(u'raise IOError("foo")')
         self.assertEqual(ip.custom_exceptions, ())
 
     def test_bad_custom_tb_return(self):
         """Check that InteractiveShell is protected from bad return types in custom exception handlers"""
         ip.set_custom_exc((NameError,),lambda etype,value,tb, tb_offset=None: 1)
         self.assertEqual(ip.custom_exceptions, (NameError,))
         with tt.AssertPrints("Custom TB Handler failed", channel='stderr'):
             ip.run_cell(u'a=abracadabra')
         self.assertEqual(ip.custom_exceptions, ())
 
     def test_drop_by_id(self):
         myvars = {"a":object(), "b":object(), "c": object()}
         ip.push(myvars, interactive=False)
         for name in myvars:
             assert name in ip.user_ns, name
             assert name in ip.user_ns_hidden, name
         ip.user_ns['b'] = 12
         ip.drop_by_id(myvars)
         for name in ["a", "c"]:
             assert name not in ip.user_ns, name
             assert name not in ip.user_ns_hidden, name
         assert ip.user_ns['b'] == 12
         ip.reset()
 
     def test_var_expand(self):
         ip.user_ns['f'] = u'Ca\xf1o'
         self.assertEqual(ip.var_expand(u'echo $f'), u'echo Ca\xf1o')
         self.assertEqual(ip.var_expand(u'echo {f}'), u'echo Ca\xf1o')
         self.assertEqual(ip.var_expand(u'echo {f[:-1]}'), u'echo Ca\xf1')
         self.assertEqual(ip.var_expand(u'echo {1*2}'), u'echo 2')
         
         self.assertEqual(ip.var_expand(u"grep x | awk '{print $1}'"), u"grep x | awk '{print $1}'")
 
         ip.user_ns['f'] = b'Ca\xc3\xb1o'
         # This should not raise any exception:
         ip.var_expand(u'echo $f')
    
     def test_var_expand_local(self):
         """Test local variable expansion in !system and %magic calls"""
         # !system
         ip.run_cell('def test():\n'
                     '    lvar = "ttt"\n'
                     '    ret = !echo {lvar}\n'
                     '    return ret[0]\n')
         res = ip.user_ns['test']()
         nt.assert_in('ttt', res)
         
         # %magic
         ip.run_cell('def makemacro():\n'
                     '    macroname = "macro_var_expand_locals"\n'
                     '    %macro {macroname} codestr\n')
         ip.user_ns['codestr'] = "str(12)"
         ip.run_cell('makemacro()')
         nt.assert_in('macro_var_expand_locals', ip.user_ns)
     
     def test_var_expand_self(self):
         """Test variable expansion with the name 'self', which was failing.
         
         See https://github.com/ipython/ipython/issues/1878#issuecomment-7698218
         """
         ip.run_cell('class cTest:\n'
                     '  classvar="see me"\n'
                     '  def test(self):\n'
                     '    res = !echo Variable: {self.classvar}\n'
                     '    return res[0]\n')
         nt.assert_in('see me', ip.user_ns['cTest']().test())
     
     def test_bad_var_expand(self):
         """var_expand on invalid formats shouldn't raise"""
         # SyntaxError
         self.assertEqual(ip.var_expand(u"{'a':5}"), u"{'a':5}")
         # NameError
         self.assertEqual(ip.var_expand(u"{asdf}"), u"{asdf}")
         # ZeroDivisionError
         self.assertEqual(ip.var_expand(u"{1/0}"), u"{1/0}")
     
     def test_silent_postexec(self):
         """run_cell(silent=True) doesn't invoke pre/post_run_cell callbacks"""
         pre_explicit = mock.Mock()
         pre_always = mock.Mock()
         post_explicit = mock.Mock()
         post_always = mock.Mock()
         all_mocks = [pre_explicit, pre_always, post_explicit, post_always]
         
         ip.events.register('pre_run_cell', pre_explicit)
         ip.events.register('pre_execute', pre_always)
         ip.events.register('post_run_cell', post_explicit)
         ip.events.register('post_execute', post_always)
         
         try:
             ip.run_cell("1", silent=True)
             assert pre_always.called
             assert not pre_explicit.called
             assert post_always.called
             assert not post_explicit.called
+            request, = pre_always.call_args[0]
+            result, = post_always.call_args[0]
+            self.assertEqual(request, result.request)
             # double-check that non-silent exec did what we expected
             # silent to avoid
             ip.run_cell("1")
             assert pre_explicit.called
             assert post_explicit.called
             # check that post hooks are always called
             [m.reset_mock() for m in all_mocks]
             ip.run_cell("syntax error")
             assert pre_always.called
             assert pre_explicit.called
             assert post_always.called
             assert post_explicit.called
+            request, = pre_always.call_args[0]
+            result, = post_always.call_args[0]
+            self.assertEqual(request, result.request)
         finally:
             # remove post-exec
             ip.events.unregister('pre_run_cell', pre_explicit)
             ip.events.unregister('pre_execute', pre_always)
             ip.events.unregister('post_run_cell', post_explicit)
             ip.events.unregister('post_execute', post_always)
     
     def test_silent_noadvance(self):
         """run_cell(silent=True) doesn't advance execution_count"""
         ec = ip.execution_count
         # silent should force store_history=False
         ip.run_cell("1", store_history=True, silent=True)
         
         self.assertEqual(ec, ip.execution_count)
         # double-check that non-silent exec did what we expected
         # silent to avoid
         ip.run_cell("1", store_history=True)
         self.assertEqual(ec+1, ip.execution_count)
     
     def test_silent_nodisplayhook(self):
         """run_cell(silent=True) doesn't trigger displayhook"""
         d = dict(called=False)
         
         trap = ip.display_trap
         save_hook = trap.hook
         
         def failing_hook(*args, **kwargs):
             d['called'] = True
         
         try:
             trap.hook = failing_hook
             res = ip.run_cell("1", silent=True)
             self.assertFalse(d['called'])
             self.assertIsNone(res.result)
             # double-check that non-silent exec did what we expected
             # silent to avoid
             ip.run_cell("1")
             self.assertTrue(d['called'])
         finally:
             trap.hook = save_hook
 
     def test_ofind_line_magic(self):
         from IPython.core.magic import register_line_magic
         
         @register_line_magic
         def lmagic(line):
             "A line magic"
 
         # Get info on line magic
         lfind = ip._ofind('lmagic')
         info = dict(found=True, isalias=False, ismagic=True,
                     namespace = 'IPython internal', obj= lmagic.__wrapped__,
                     parent = None)
         nt.assert_equal(lfind, info)
         
     def test_ofind_cell_magic(self):
         from IPython.core.magic import register_cell_magic
         
         @register_cell_magic
         def cmagic(line, cell):
             "A cell magic"
 
         # Get info on cell magic
         find = ip._ofind('cmagic')
         info = dict(found=True, isalias=False, ismagic=True,
                     namespace = 'IPython internal', obj= cmagic.__wrapped__,
                     parent = None)
         nt.assert_equal(find, info)
 
     def test_ofind_property_with_error(self):
         class A(object):
             @property
             def foo(self):
                 raise NotImplementedError()
         a = A()
 
         found = ip._ofind('a.foo', [('locals', locals())])
         info = dict(found=True, isalias=False, ismagic=False,
                     namespace='locals', obj=A.foo, parent=a)
         nt.assert_equal(found, info)
 
     def test_ofind_multiple_attribute_lookups(self):
         class A(object):
             @property
             def foo(self):
                 raise NotImplementedError()
 
         a = A()
         a.a = A()
         a.a.a = A()
 
         found = ip._ofind('a.a.a.foo', [('locals', locals())])
         info = dict(found=True, isalias=False, ismagic=False,
                     namespace='locals', obj=A.foo, parent=a.a.a)
         nt.assert_equal(found, info)
 
     def test_ofind_slotted_attributes(self):
         class A(object):
             __slots__ = ['foo']
             def __init__(self):
                 self.foo = 'bar'
 
         a = A()
         found = ip._ofind('a.foo', [('locals', locals())])
         info = dict(found=True, isalias=False, ismagic=False,
                     namespace='locals', obj=a.foo, parent=a)
         nt.assert_equal(found, info)
 
         found = ip._ofind('a.bar', [('locals', locals())])
         info = dict(found=False, isalias=False, ismagic=False,
                     namespace=None, obj=None, parent=a)
         nt.assert_equal(found, info)
 
     def test_ofind_prefers_property_to_instance_level_attribute(self):
         class A(object):
             @property
             def foo(self):
                 return 'bar'
         a = A()
         a.__dict__['foo'] = 'baz'
         nt.assert_equal(a.foo, 'bar')
         found = ip._ofind('a.foo', [('locals', locals())])
         nt.assert_is(found['obj'], A.foo)
 
     def test_custom_syntaxerror_exception(self):
         called = []
         def my_handler(shell, etype, value, tb, tb_offset=None):
             called.append(etype)
             shell.showtraceback((etype, value, tb), tb_offset=tb_offset)
 
         ip.set_custom_exc((SyntaxError,), my_handler)
         try:
             ip.run_cell("1f")
             # Check that this was called, and only once.
             self.assertEqual(called, [SyntaxError])
         finally:
             # Reset the custom exception hook
             ip.set_custom_exc((), None)
 
     def test_custom_exception(self):
         called = []
         def my_handler(shell, etype, value, tb, tb_offset=None):
             called.append(etype)
             shell.showtraceback((etype, value, tb), tb_offset=tb_offset)
         
         ip.set_custom_exc((ValueError,), my_handler)
         try:
             res = ip.run_cell("raise ValueError('test')")
             # Check that this was called, and only once.
             self.assertEqual(called, [ValueError])
             # Check that the error is on the result object
             self.assertIsInstance(res.error_in_exec, ValueError)
         finally:
             # Reset the custom exception hook
             ip.set_custom_exc((), None)
     
     def test_mktempfile(self):
         filename = ip.mktempfile()
         # Check that we can open the file again on Windows
         with open(filename, 'w') as f:
             f.write('abc')
 
         filename = ip.mktempfile(data='blah')
         with open(filename, 'r') as f:
             self.assertEqual(f.read(), 'blah')
 
     def test_new_main_mod(self):
         # Smoketest to check that this accepts a unicode module name
         name = u'jiefmw'
         mod = ip.new_main_mod(u'%s.py' % name, name)
         self.assertEqual(mod.__name__, name)
 
     def test_get_exception_only(self):
         try:
             raise KeyboardInterrupt
         except KeyboardInterrupt:
             msg = ip.get_exception_only()
         self.assertEqual(msg, 'KeyboardInterrupt\n')
 
         try:
             raise DerivedInterrupt("foo")
         except KeyboardInterrupt:
             msg = ip.get_exception_only()
         self.assertEqual(msg, 'IPython.core.tests.test_interactiveshell.DerivedInterrupt: foo\n')
 
     def test_inspect_text(self):
         ip.run_cell('a = 5')
         text = ip.object_inspect_text('a')
         self.assertIsInstance(text, str)
 
     def test_last_execution_result(self):
         """ Check that last execution result gets set correctly (GH-10702) """
         result = ip.run_cell('a = 5; a')
         self.assertTrue(ip.last_execution_succeeded)
         self.assertEqual(ip.last_execution_result.result, 5)
 
         result = ip.run_cell('a = x_invalid_id_x')
         self.assertFalse(ip.last_execution_succeeded)
         self.assertFalse(ip.last_execution_result.success)
         self.assertIsInstance(ip.last_execution_result.error_in_exec, NameError)
 
 
 class TestSafeExecfileNonAsciiPath(unittest.TestCase):
 
     @onlyif_unicode_paths
     def setUp(self):
         self.BASETESTDIR = tempfile.mkdtemp()
         self.TESTDIR = join(self.BASETESTDIR, u"åäö")
         os.mkdir(self.TESTDIR)
         with open(join(self.TESTDIR, u"åäötestscript.py"), "w") as sfile:
             sfile.write("pass\n")
         self.oldpath = os.getcwd()
         os.chdir(self.TESTDIR)
         self.fname = u"åäötestscript.py"
 
     def tearDown(self):
         os.chdir(self.oldpath)
         shutil.rmtree(self.BASETESTDIR)
 
     @onlyif_unicode_paths
     def test_1(self):
         """Test safe_execfile with non-ascii path
         """
         ip.safe_execfile(self.fname, {}, raise_exceptions=True)
 
 class ExitCodeChecks(tt.TempFileMixin):
     def test_exit_code_ok(self):
         self.system('exit 0')
         self.assertEqual(ip.user_ns['_exit_code'], 0)
 
     def test_exit_code_error(self):
         self.system('exit 1')
         self.assertEqual(ip.user_ns['_exit_code'], 1)
     
     @skipif(not hasattr(signal, 'SIGALRM'))
     def test_exit_code_signal(self):
         self.mktmp("import signal, time\n"
                    "signal.setitimer(signal.ITIMER_REAL, 0.1)\n"
                    "time.sleep(1)\n")
         self.system("%s %s" % (sys.executable, self.fname))
         self.assertEqual(ip.user_ns['_exit_code'], -signal.SIGALRM)
     
     @onlyif_cmds_exist("csh")
     def test_exit_code_signal_csh(self):
         SHELL = os.environ.get('SHELL', None)
         os.environ['SHELL'] = find_cmd("csh")
         try:
             self.test_exit_code_signal()
         finally:
             if SHELL is not None:
                 os.environ['SHELL'] = SHELL
             else:
                 del os.environ['SHELL']
 
 class TestSystemRaw(unittest.TestCase, ExitCodeChecks):
     system = ip.system_raw
 
     @onlyif_unicode_paths
     def test_1(self):
         """Test system_raw with non-ascii cmd
         """
         cmd = u'''python -c "'åäö'"   '''
         ip.system_raw(cmd)
 
     @mock.patch('subprocess.call', side_effect=KeyboardInterrupt)
     @mock.patch('os.system', side_effect=KeyboardInterrupt)
     def test_control_c(self, *mocks):
         try:
             self.system("sleep 1 # wont happen")
         except KeyboardInterrupt:
             self.fail("system call should intercept "
                       "keyboard interrupt from subprocess.call")
         self.assertEqual(ip.user_ns['_exit_code'], -signal.SIGINT)
 
 # TODO: Exit codes are currently ignored on Windows.
 class TestSystemPipedExitCode(unittest.TestCase, ExitCodeChecks):
     system = ip.system_piped
 
     @skip_win32
     def test_exit_code_ok(self):
         ExitCodeChecks.test_exit_code_ok(self)
 
     @skip_win32
     def test_exit_code_error(self):
         ExitCodeChecks.test_exit_code_error(self)
 
     @skip_win32
     def test_exit_code_signal(self):
         ExitCodeChecks.test_exit_code_signal(self)
 
 class TestModules(unittest.TestCase, tt.TempFileMixin):
     def test_extraneous_loads(self):
         """Test we're not loading modules on startup that we shouldn't.
         """
         self.mktmp("import sys\n"
                    "print('numpy' in sys.modules)\n"
                    "print('ipyparallel' in sys.modules)\n"
                    "print('ipykernel' in sys.modules)\n"
                    )
         out = "False\nFalse\nFalse\n"
         tt.ipexec_validate(self.fname, out)
 
 class Negator(ast.NodeTransformer):
     """Negates all number literals in an AST."""
     def visit_Num(self, node):
         node.n = -node.n
         return node
 
 class TestAstTransform(unittest.TestCase):
     def setUp(self):
         self.negator = Negator()
         ip.ast_transformers.append(self.negator)
     
     def tearDown(self):
         ip.ast_transformers.remove(self.negator)
     
     def test_run_cell(self):
         with tt.AssertPrints('-34'):
             ip.run_cell('print (12 + 22)')
         
         # A named reference to a number shouldn't be transformed.
         ip.user_ns['n'] = 55
         with tt.AssertNotPrints('-55'):
             ip.run_cell('print (n)')
     
     def test_timeit(self):
         called = set()
         def f(x):
             called.add(x)
         ip.push({'f':f})
         
         with tt.AssertPrints("std. dev. of"):
             ip.run_line_magic("timeit", "-n1 f(1)")
         self.assertEqual(called, {-1})
         called.clear()
 
         with tt.AssertPrints("std. dev. of"):
             ip.run_cell_magic("timeit", "-n1 f(2)", "f(3)")
         self.assertEqual(called, {-2, -3})
     
     def test_time(self):
         called = []
         def f(x):
             called.append(x)
         ip.push({'f':f})
         
         # Test with an expression
         with tt.AssertPrints("Wall time: "):
             ip.run_line_magic("time", "f(5+9)")
         self.assertEqual(called, [-14])
         called[:] = []
         
         # Test with a statement (different code path)
         with tt.AssertPrints("Wall time: "):
             ip.run_line_magic("time", "a = f(-3 + -2)")
         self.assertEqual(called, [5])
     
     def test_macro(self):
         ip.push({'a':10})
         # The AST transformation makes this do a+=-1
         ip.define_macro("amacro", "a+=1\nprint(a)")
         
         with tt.AssertPrints("9"):
             ip.run_cell("amacro")
         with tt.AssertPrints("8"):
             ip.run_cell("amacro")
 
 class IntegerWrapper(ast.NodeTransformer):
     """Wraps all integers in a call to Integer()"""
     def visit_Num(self, node):
         if isinstance(node.n, int):
             return ast.Call(func=ast.Name(id='Integer', ctx=ast.Load()),
                             args=[node], keywords=[])
         return node
 
 class TestAstTransform2(unittest.TestCase):
     def setUp(self):
         self.intwrapper = IntegerWrapper()
         ip.ast_transformers.append(self.intwrapper)
         
         self.calls = []
         def Integer(*args):
             self.calls.append(args)
             return args
         ip.push({"Integer": Integer})
     
     def tearDown(self):
         ip.ast_transformers.remove(self.intwrapper)
         del ip.user_ns['Integer']
     
     def test_run_cell(self):
         ip.run_cell("n = 2")
         self.assertEqual(self.calls, [(2,)])
         
         # This shouldn't throw an error
         ip.run_cell("o = 2.0")
         self.assertEqual(ip.user_ns['o'], 2.0)
     
     def test_timeit(self):
         called = set()
         def f(x):
             called.add(x)
         ip.push({'f':f})
 
         with tt.AssertPrints("std. dev. of"):
             ip.run_line_magic("timeit", "-n1 f(1)")
         self.assertEqual(called, {(1,)})
         called.clear()
 
         with tt.AssertPrints("std. dev. of"):
             ip.run_cell_magic("timeit", "-n1 f(2)", "f(3)")
         self.assertEqual(called, {(2,), (3,)})
 
 class ErrorTransformer(ast.NodeTransformer):
     """Throws an error when it sees a number."""
     def visit_Num(self, node):
         raise ValueError("test")
 
 class TestAstTransformError(unittest.TestCase):
     def test_unregistering(self):
         err_transformer = ErrorTransformer()
         ip.ast_transformers.append(err_transformer)
         
         with tt.AssertPrints("unregister", channel='stderr'):
             ip.run_cell("1 + 2")
         
         # This should have been removed.
         nt.assert_not_in(err_transformer, ip.ast_transformers)
 
 
 class StringRejector(ast.NodeTransformer):
     """Throws an InputRejected when it sees a string literal.
 
     Used to verify that NodeTransformers can signal that a piece of code should
     not be executed by throwing an InputRejected.
     """
 
     def visit_Str(self, node):
         raise InputRejected("test")
 
 
 class TestAstTransformInputRejection(unittest.TestCase):
 
     def setUp(self):
         self.transformer = StringRejector()
         ip.ast_transformers.append(self.transformer)
 
     def tearDown(self):
         ip.ast_transformers.remove(self.transformer)
 
     def test_input_rejection(self):
         """Check that NodeTransformers can reject input."""
 
         expect_exception_tb = tt.AssertPrints("InputRejected: test")
         expect_no_cell_output = tt.AssertNotPrints("'unsafe'", suppress=False)
 
         # Run the same check twice to verify that the transformer is not
         # disabled after raising.
         with expect_exception_tb, expect_no_cell_output:
             ip.run_cell("'unsafe'")
 
         with expect_exception_tb, expect_no_cell_output:
             res = ip.run_cell("'unsafe'")
 
         self.assertIsInstance(res.error_before_exec, InputRejected)
 
 def test__IPYTHON__():
     # This shouldn't raise a NameError, that's all
     __IPYTHON__
 
 
 class DummyRepr(object):
     def __repr__(self):
         return "DummyRepr"
     
     def _repr_html_(self):
         return "<b>dummy</b>"
     
     def _repr_javascript_(self):
         return "console.log('hi');", {'key': 'value'}
     
 
 def test_user_variables():
     # enable all formatters
     ip.display_formatter.active_types = ip.display_formatter.format_types
     
     ip.user_ns['dummy'] = d = DummyRepr()
     keys = {'dummy', 'doesnotexist'}
     r = ip.user_expressions({ key:key for key in keys})
 
     nt.assert_equal(keys, set(r.keys()))
     dummy = r['dummy']
     nt.assert_equal({'status', 'data', 'metadata'}, set(dummy.keys()))
     nt.assert_equal(dummy['status'], 'ok')
     data = dummy['data']
     metadata = dummy['metadata']
     nt.assert_equal(data.get('text/html'), d._repr_html_())
     js, jsmd = d._repr_javascript_()
     nt.assert_equal(data.get('application/javascript'), js)
     nt.assert_equal(metadata.get('application/javascript'), jsmd)
     
     dne = r['doesnotexist']
     nt.assert_equal(dne['status'], 'error')
     nt.assert_equal(dne['ename'], 'NameError')
     
     # back to text only
     ip.display_formatter.active_types = ['text/plain']
     
 def test_user_expression():
     # enable all formatters
     ip.display_formatter.active_types = ip.display_formatter.format_types
     query = {
         'a' : '1 + 2',
         'b' : '1/0',
     }
     r = ip.user_expressions(query)
     import pprint
     pprint.pprint(r)
     nt.assert_equal(set(r.keys()), set(query.keys()))
     a = r['a']
     nt.assert_equal({'status', 'data', 'metadata'}, set(a.keys()))
     nt.assert_equal(a['status'], 'ok')
     data = a['data']
     metadata = a['metadata']
     nt.assert_equal(data.get('text/plain'), '3')
     
     b = r['b']
     nt.assert_equal(b['status'], 'error')
     nt.assert_equal(b['ename'], 'ZeroDivisionError')
     
     # back to text only
     ip.display_formatter.active_types = ['text/plain']
     
 
 
 
 
 class TestSyntaxErrorTransformer(unittest.TestCase):
     """Check that SyntaxError raised by an input transformer is handled by run_cell()"""
 
     class SyntaxErrorTransformer(InputTransformer):
 
         def push(self, line):
             pos = line.find('syntaxerror')
             if pos >= 0:
                 e = SyntaxError('input contains "syntaxerror"')
                 e.text = line
                 e.offset = pos + 1
                 raise e
             return line
 
         def reset(self):
             pass
 
     def setUp(self):
         self.transformer = TestSyntaxErrorTransformer.SyntaxErrorTransformer()
         ip.input_splitter.python_line_transforms.append(self.transformer)
         ip.input_transformer_manager.python_line_transforms.append(self.transformer)
 
     def tearDown(self):
         ip.input_splitter.python_line_transforms.remove(self.transformer)
         ip.input_transformer_manager.python_line_transforms.remove(self.transformer)
 
     def test_syntaxerror_input_transformer(self):
         with tt.AssertPrints('1234'):
             ip.run_cell('1234')
         with tt.AssertPrints('SyntaxError: invalid syntax'):
             ip.run_cell('1 2 3')   # plain python syntax error
         with tt.AssertPrints('SyntaxError: input contains "syntaxerror"'):
             ip.run_cell('2345  # syntaxerror')  # input transformer syntax error
         with tt.AssertPrints('3456'):
             ip.run_cell('3456')
 
 
 
 def test_warning_suppression():
     ip.run_cell("import warnings")
     try:
         with tt.AssertPrints("UserWarning: asdf", channel="stderr"):
             ip.run_cell("warnings.warn('asdf')")
         # Here's the real test -- if we run that again, we should get the
         # warning again. Traditionally, each warning was only issued once per
         # IPython session (approximately), even if the user typed in new and
         # different code that should have also triggered the warning, leading
         # to much confusion.
         with tt.AssertPrints("UserWarning: asdf", channel="stderr"):
             ip.run_cell("warnings.warn('asdf')")
     finally:
         ip.run_cell("del warnings")
 
 
 def test_deprecation_warning():
     ip.run_cell("""
 import warnings
 def wrn():
     warnings.warn(
         "I AM  A WARNING",
         DeprecationWarning
     )
         """)
     try:
         with tt.AssertPrints("I AM  A WARNING", channel="stderr"):
             ip.run_cell("wrn()")
     finally:
         ip.run_cell("del warnings")
         ip.run_cell("del wrn")
 
 
 class TestImportNoDeprecate(tt.TempFileMixin):
 
     def setup(self):
         """Make a valid python temp file."""
         self.mktmp("""
 import warnings
 def wrn():
     warnings.warn(
         "I AM  A WARNING",
         DeprecationWarning
     )
 """)
 
     def test_no_dep(self):
         """
         No deprecation warning should be raised from imported functions
         """
         ip.run_cell("from {} import wrn".format(self.fname))
 
         with tt.AssertNotPrints("I AM  A WARNING"):
             ip.run_cell("wrn()")
         ip.run_cell("del wrn")

docs/source/config/callbacks.rst

@@ -1,94 +1,94 b''
 .. _events:
 .. _callbacks:
 
 ==============
 IPython Events
 ==============
 
 Extension code can register callbacks functions which will be called on specific
 events within the IPython code. You can see the current list of available
 callbacks, and the parameters that will be passed with each, in the callback
 prototype functions defined in :mod:`IPython.core.callbacks`.
 
 To register callbacks, use :meth:`IPython.core.events.EventManager.register`.
 For example::
 
     class VarWatcher(object):
         def __init__(self, ip):
             self.shell = ip
             self.last_x = None
         
-        def pre_execute(self):
+        def pre_execute(self, request):
+            print('Cell code: "%s"' % request.raw_cell)
             self.last_x = self.shell.user_ns.get('x', None)
         
         def post_execute(self, result):
+            print('Cell code: "%s"' % result.request.raw_cell)
             if result.error_before_exec:
                 print('Error before execution: %s' % result.error_before_exec)
             if self.shell.user_ns.get('x', None) != self.last_x:
                 print("x changed!")
         
     def load_ipython_extension(ip):
         vw = VarWatcher(ip)
         ip.events.register('pre_execute', vw.pre_execute)
         ip.events.register('post_execute', vw.post_execute)
 
 
 Events
 ======
 
 These are the events IPython will emit. Callbacks will be passed no arguments, unless otherwise specified.
 
 shell_initialized
 -----------------
 
 .. code-block:: python
 
     def shell_initialized(ipython):
         ...
 
 This event is triggered only once, at the end of setting up IPython.
 Extensions registered to load by default as part of configuration can use this to execute code to finalize setup.
 Callbacks will be passed the InteractiveShell instance.
 
 pre_run_cell
 ------------
 
 ``pre_run_cell`` fires prior to interactive execution (e.g. a cell in a notebook).
 It can be used to note the state prior to execution, and keep track of changes.
-The object which will be returned as the execution result is provided as an
-argument, even though the actual result is not yet available.
+The object representing the code execution request is provided as an argument.
 
 pre_execute
 -----------
 
 ``pre_execute`` is like ``pre_run_cell``, but is triggered prior to *any* execution.
 Sometimes code can be executed by libraries, etc. which
 skipping the history/display mechanisms, in which cases ``pre_run_cell`` will not fire.
-The object which will be returned as the execution result is provided as an
-argument, even though the actual result is not yet available.
+The object representing the code execution request is provided as an argument.
 
 post_run_cell
 -------------
 
 ``post_run_cell`` runs after interactive execution (e.g. a cell in a notebook).
 It can be used to cleanup or notify or perform operations on any side effects produced during execution.
 For instance, the inline matplotlib backend uses this event to display any figures created but not explicitly displayed during the course of the cell.
 The object which will be returned as the execution result is provided as an
 argument.
 
 post_execute
 ------------
 
 The same as ``pre_execute``, ``post_execute`` is like ``post_run_cell``,
 but fires for *all* executions, not just interactive ones.
 
 
 .. seealso::
 
    Module :mod:`IPython.core.hooks`
      The older 'hooks' system allows end users to customise some parts of
      IPython's behaviour.
    
    :doc:`inputtransforms`
      By registering input transformers that don't change code, you can monitor
      what is being executed.

docs/source/whatsnew/pr/event-callbacks-updates.rst

@@ -1,6 +1,7 b''
 The *post* event callbacks are now always called, even when the execution failed
 (for example because of a ``SyntaxError``).
-Additionally, the execution result object is now made available in both *pre*
-and *post* event callbacks in a backward compatible manner.
+Additionally, the execution request and result objects are now made available in
+the corresponding *pre* or *post* event callbacks in a backward compatible
+manner.
 
 * `Related GitHub issue <https://github.com/ipython/ipython/issues/10774>`__

setup.py

@@ -1,265 +1,266 b''
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 """Setup script for IPython.
 
 Under Posix environments it works like a typical setup.py script.
 Under Windows, the command sdist is not supported, since IPython
 requires utilities which are not available under Windows."""
 
 #-----------------------------------------------------------------------------
 #  Copyright (c) 2008-2011, IPython Development Team.
 #  Copyright (c) 2001-2007, Fernando Perez <[e-mail]>
 #  Copyright (c) 2001, Janko Hauser <[e-mail]>
 #  Copyright (c) 2001, Nathaniel Gray <[e-mail]>
 #
 #  Distributed under the terms of the Modified BSD License.
 #
 #  The full license is in the file COPYING.rst, distributed with this software.
 #-----------------------------------------------------------------------------
 
 from __future__ import print_function
 
 import os
 import sys
 
 # **Python version check**
 #
 # This check is also made in IPython/__init__, don't forget to update both when
 # changing Python version requirements.
 if sys.version_info < (3, 3):
     pip_message = 'This may be due to an out of date pip. Make sure you have pip >= 9.0.1.'
     try:
         import pip
         pip_version = tuple([int(x) for x in pip.__version__.split('.')[:3]])
         if pip_version < (9, 0, 1) :
             pip_message = 'Your pip version is out of date, please install pip >= 9.0.1. '\
             'pip {} detected.'.format(pip.__version__)
         else:
             # pip is new enough - it must be something else
             pip_message = ''
     except Exception:
         pass
 
         
     error = """
 IPython 6.0+ does not support Python 2.6, 2.7, 3.0, 3.1, or 3.2.
 When using Python 2.7, please install IPython 5.x LTS Long Term Support version.
 Beginning with IPython 6.0, Python 3.3 and above is required.
 
 See IPython `README.rst` file for more information:
 
     https://github.com/ipython/ipython/blob/master/README.rst
 
 Python {py} detected.
 {pip}
 """.format(py=sys.version_info, pip=pip_message )
 
     print(error, file=sys.stderr)
     sys.exit(1)
 
 # At least we're on the python version we need, move on.
 
 # BEFORE importing distutils, remove MANIFEST. distutils doesn't properly
 # update it when the contents of directories change.
 if os.path.exists('MANIFEST'): os.remove('MANIFEST')
 
 from distutils.core import setup
 
 # Our own imports
 from setupbase import target_update
 
 from setupbase import (
     setup_args,
     find_packages,
     find_package_data,
     check_package_data_first,
     find_entry_points,
     build_scripts_entrypt,
     find_data_files,
     git_prebuild,
     install_symlinked,
     install_lib_symlink,
     install_scripts_for_symlink,
     unsymlink,
 )
 
 isfile = os.path.isfile
 pjoin = os.path.join
 
 #-------------------------------------------------------------------------------
 # Handle OS specific things
 #-------------------------------------------------------------------------------
 
 if os.name in ('nt','dos'):
     os_name = 'windows'
 else:
     os_name = os.name
 
 # Under Windows, 'sdist' has not been supported.  Now that the docs build with
 # Sphinx it might work, but let's not turn it on until someone confirms that it
 # actually works.
 if os_name == 'windows' and 'sdist' in sys.argv:
     print('The sdist command is not available under Windows.  Exiting.')
     sys.exit(1)
 
 
 #-------------------------------------------------------------------------------
 # Things related to the IPython documentation
 #-------------------------------------------------------------------------------
 
 # update the manuals when building a source dist
 if len(sys.argv) >= 2 and sys.argv[1] in ('sdist','bdist_rpm'):
 
     # List of things to be updated. Each entry is a triplet of args for
     # target_update()
     to_update = [
                  ('docs/man/ipython.1.gz',
                   ['docs/man/ipython.1'],
                   'cd docs/man && gzip -9c ipython.1 > ipython.1.gz'),
                  ]
 
 
     [ target_update(*t) for t in to_update ]
 
 #---------------------------------------------------------------------------
 # Find all the packages, package data, and data_files
 #---------------------------------------------------------------------------
 
 packages = find_packages()
 package_data = find_package_data()
 
 data_files = find_data_files()
 
 setup_args['packages'] = packages
 setup_args['package_data'] = package_data
 setup_args['data_files'] = data_files
 
 #---------------------------------------------------------------------------
 # custom distutils commands
 #---------------------------------------------------------------------------
 # imports here, so they are after setuptools import if there was one
 from distutils.command.sdist import sdist
 
 setup_args['cmdclass'] = {
     'build_py': \
             check_package_data_first(git_prebuild('IPython')),
     'sdist' : git_prebuild('IPython', sdist),
     'symlink': install_symlinked,
     'install_lib_symlink': install_lib_symlink,
     'install_scripts_sym': install_scripts_for_symlink,
     'unsymlink': unsymlink,
 }
 
 
 #---------------------------------------------------------------------------
 # Handle scripts, dependencies, and setuptools specific things
 #---------------------------------------------------------------------------
 
 # For some commands, use setuptools.  Note that we do NOT list install here!
 # If you want a setuptools-enhanced install, just run 'setupegg.py install'
 needs_setuptools = {'develop', 'release', 'bdist_egg', 'bdist_rpm',
            'bdist', 'bdist_dumb', 'bdist_wininst', 'bdist_wheel',
            'egg_info', 'easy_install', 'upload', 'install_egg_info',
           }
 
 if len(needs_setuptools.intersection(sys.argv)) > 0:
     import setuptools
 
 # This dict is used for passing extra arguments that are setuptools
 # specific to setup
 setuptools_extra_args = {}
 
 # setuptools requirements
 
 extras_require = dict(
     parallel = ['ipyparallel'],
     qtconsole = ['qtconsole'],
     doc = ['Sphinx>=1.3'],
     test = ['nose>=0.10.1', 'requests', 'testpath', 'pygments', 'nbformat', 'ipykernel'],
     terminal = [],
     kernel = ['ipykernel'],
     nbformat = ['nbformat'],
     notebook = ['notebook', 'ipywidgets'],
     nbconvert = ['nbconvert'],
 )
 
 install_requires = [
     'setuptools>=18.5',
     'jedi>=0.10',
     'decorator',
     'pickleshare',
     'simplegeneric>0.8',
     'traitlets>=4.2',
     'prompt_toolkit>=1.0.4,<2.0.0',
     'pygments',
+    'backcall',
 ]
 
 # Platform-specific dependencies:
 # This is the correct way to specify these,
 # but requires pip >= 6. pip < 6 ignores these.
 
 extras_require.update({
     'test:python_version >= "3.4"': ['numpy'],
     ':python_version == "3.3"': ['pathlib2'],
     ':python_version <= "3.4"': ['typing'],
     ':sys_platform != "win32"': ['pexpect'],
     ':sys_platform == "darwin"': ['appnope'],
     ':sys_platform == "win32"': ['colorama'],
     ':sys_platform == "win32" and python_version < "3.6"': ['win_unicode_console>=0.5'],
 })
 # FIXME: re-specify above platform dependencies for pip < 6
 # These would result in non-portable bdists.
 if not any(arg.startswith('bdist') for arg in sys.argv):
     if sys.platform == 'darwin':
         install_requires.extend(['appnope'])
 
     if not sys.platform.startswith('win'):
         install_requires.append('pexpect')
 
     # workaround pypa/setuptools#147, where setuptools misspells
     # platform_python_implementation as python_implementation
     if 'setuptools' in sys.modules:
         for key in list(extras_require):
             if 'platform_python_implementation' in key:
                 new_key = key.replace('platform_python_implementation', 'python_implementation')
                 extras_require[new_key] = extras_require.pop(key)
 
 everything = set()
 for key, deps in extras_require.items():
     if ':' not in key:
         everything.update(deps)
 extras_require['all'] = everything
 
 if 'setuptools' in sys.modules:
     setuptools_extra_args['python_requires'] = '>=3.3'
     setuptools_extra_args['zip_safe'] = False
     setuptools_extra_args['entry_points'] = {
         'console_scripts': find_entry_points(),
         'pygments.lexers': [
             'ipythonconsole = IPython.lib.lexers:IPythonConsoleLexer',
             'ipython = IPython.lib.lexers:IPythonLexer',
             'ipython3 = IPython.lib.lexers:IPython3Lexer',
         ],
     }
     setup_args['extras_require'] = extras_require
     setup_args['install_requires'] = install_requires
 
 else:
     # scripts has to be a non-empty list, or install_scripts isn't called
     setup_args['scripts'] = [e.split('=')[0].strip() for e in find_entry_points()]
 
     setup_args['cmdclass']['build_scripts'] = build_scripts_entrypt
 
 #---------------------------------------------------------------------------
 # Do the actual setup now
 #---------------------------------------------------------------------------
 
 setup_args.update(setuptools_extra_args)
 
 
 
 def main():
     setup(**setup_args)
 
 if __name__ == '__main__':
     main()