##// END OF EJS Templates
Swallow potential exceptions from showtraceback()...
Swallow potential exceptions from showtraceback() The nbgrader project is aware of a form of cheating where students disrupt `InteractiveShell.showtraceback` in hopes of hiding exceptions to avoid losing points. They have implemented a solution to prevent this cheating from working on the client side, and have some tests to demonstrate this technique: https://github.com/jupyter/nbgrader/blob/main/nbgrader/tests/apps/files/submitted-cheat-attempt.ipynb https://github.com/jupyter/nbgrader/blob/main/nbgrader/tests/apps/files/submitted-cheat-attempt-alternative.ipynb In essence, these attacks import the interactive shell and erase the traceback handler so that their failing tests won't report failures. import IPython.core.interactiveshell IPython.core.interactiveshell.InteractiveShell.showtraceback = None The problem is that this causes an exception inside the kernel, leading to a stalled execution. The kernel has stopped working, but the client continues to wait for messages. So far, nbgrader's solution to this is to require a timeout value so the client can eventually decide it is done. This prevents allowing a value of `None` for `Execute.timeout` because this would cause a test case to infinitely hang. This commit addresses the problem by making `InteractiveShell._run_cell` a little more protective around it's call to `showtraceback()`. There is already a try/except block around running the cell. This commit adds a finally clause so that the method will _always_ return an `ExecutionResult`, even if a new exception is thrown within the except clause. For the record, the exception thrown is: TypeError: 'NoneType' object is not callable Accepting this change will allow nbgrader to update `nbgrader.preprocessors.Execute` to support a type of `Integer(allow_none=True)` as the parent `NotebookClient` intended. Discussion about this is ongoing in jupyter/nbgrader#1690.

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__init__.py
156 lines | 5.8 KiB | text/x-python | PythonLexer
# PYTHON_ARGCOMPLETE_OK
"""
IPython: tools for interactive and parallel computing in Python.
https://ipython.org
"""
#-----------------------------------------------------------------------------
# Copyright (c) 2008-2011, IPython Development Team.
# Copyright (c) 2001-2007, Fernando Perez <fernando.perez@colorado.edu>
# Copyright (c) 2001, Janko Hauser <jhauser@zscout.de>
# Copyright (c) 2001, Nathaniel Gray <n8gray@caltech.edu>
#
# Distributed under the terms of the Modified BSD License.
#
# The full license is in the file COPYING.txt, distributed with this software.
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
import sys
#-----------------------------------------------------------------------------
# Setup everything
#-----------------------------------------------------------------------------
# Don't forget to also update setup.py when this changes!
if sys.version_info < (3, 8):
raise ImportError(
"""
IPython 8+ supports Python 3.8 and above, following NEP 29.
When using Python 2.7, please install IPython 5.x LTS Long Term Support version.
Python 3.3 and 3.4 were supported up to IPython 6.x.
Python 3.5 was supported with IPython 7.0 to 7.9.
Python 3.6 was supported with IPython up to 7.16.
Python 3.7 was still supported with the 7.x branch.
See IPython `README.rst` file for more information:
https://github.com/ipython/ipython/blob/main/README.rst
"""
)
#-----------------------------------------------------------------------------
# Setup the top level names
#-----------------------------------------------------------------------------
from .core.getipython import get_ipython
from .core import release
from .core.application import Application
from .terminal.embed import embed
from .core.interactiveshell import InteractiveShell
from .utils.sysinfo import sys_info
from .utils.frame import extract_module_locals
# Release data
__author__ = '%s <%s>' % (release.author, release.author_email)
__license__ = release.license
__version__ = release.version
version_info = release.version_info
# list of CVEs that should have been patched in this release.
# this is informational and should not be relied upon.
__patched_cves__ = {"CVE-2022-21699"}
def embed_kernel(module=None, local_ns=None, **kwargs):
"""Embed and start an IPython kernel in a given scope.
If you don't want the kernel to initialize the namespace
from the scope of the surrounding function,
and/or you want to load full IPython configuration,
you probably want `IPython.start_kernel()` instead.
Parameters
----------
module : types.ModuleType, optional
The module to load into IPython globals (default: caller)
local_ns : dict, optional
The namespace to load into IPython user namespace (default: caller)
**kwargs : various, optional
Further keyword args are relayed to the IPKernelApp constructor,
allowing configuration of the Kernel. Will only have an effect
on the first embed_kernel call for a given process.
"""
(caller_module, caller_locals) = extract_module_locals(1)
if module is None:
module = caller_module
if local_ns is None:
local_ns = caller_locals
# Only import .zmq when we really need it
from ipykernel.embed import embed_kernel as real_embed_kernel
real_embed_kernel(module=module, local_ns=local_ns, **kwargs)
def start_ipython(argv=None, **kwargs):
"""Launch a normal IPython instance (as opposed to embedded)
`IPython.embed()` puts a shell in a particular calling scope,
such as a function or method for debugging purposes,
which is often not desirable.
`start_ipython()` does full, regular IPython initialization,
including loading startup files, configuration, etc.
much of which is skipped by `embed()`.
This is a public API method, and will survive implementation changes.
Parameters
----------
argv : list or None, optional
If unspecified or None, IPython will parse command-line options from sys.argv.
To prevent any command-line parsing, pass an empty list: `argv=[]`.
user_ns : dict, optional
specify this dictionary to initialize the IPython user namespace with particular values.
**kwargs : various, optional
Any other kwargs will be passed to the Application constructor,
such as `config`.
"""
from IPython.terminal.ipapp import launch_new_instance
return launch_new_instance(argv=argv, **kwargs)
def start_kernel(argv=None, **kwargs):
"""Launch a normal IPython kernel instance (as opposed to embedded)
`IPython.embed_kernel()` puts a shell in a particular calling scope,
such as a function or method for debugging purposes,
which is often not desirable.
`start_kernel()` does full, regular IPython initialization,
including loading startup files, configuration, etc.
much of which is skipped by `embed()`.
Parameters
----------
argv : list or None, optional
If unspecified or None, IPython will parse command-line options from sys.argv.
To prevent any command-line parsing, pass an empty list: `argv=[]`.
user_ns : dict, optional
specify this dictionary to initialize the IPython user namespace with particular values.
**kwargs : various, optional
Any other kwargs will be passed to the Application constructor,
such as `config`.
"""
import warnings
warnings.warn(
"start_kernel is deprecated since IPython 8.0, use from `ipykernel.kernelapp.launch_new_instance`",
DeprecationWarning,
stacklevel=2,
)
from ipykernel.kernelapp import launch_new_instance
return launch_new_instance(argv=argv, **kwargs)