##// END OF EJS Templates
Backport PR #9976: Let IPython.lib.guisupport detect terminal-integrated event loops...
Backport PR #9976: Let IPython.lib.guisupport detect terminal-integrated event loops Closes gh-9974 This is a bit more invasive than most backported changes, but it fixes a regression in IPython 5. My thinking: - The `guisupport` APIs that worked before should continue working until/unless we deprecate them. - There should be a common way to check if an event loop is already running in both the terminal and an IPython kernel. - It should be possible to check for any event loop, not just Qt and Wx (which `guisupport` has checks for). My plan is to make a public attribute `shell.active_eventloop`, which is either None or a string naming the event loop which IPython will run when waiting for input. E.g. `qt` or `gtk3`. (Todo: should we also expose the event loop object in cases where there is one? Not sure if anything useful can be done with it). This PR adds that attribute for terminal IPython; if we agree on it I'll make a separate PR for ipykernel. The functions in guisupport then become a convenient shortcut for checking this, and we can decide whether to deprecate them in favour or something more uniform, or add similar convenience functions for other common event loops. Signed-off-by: Thomas Kluyver <thomas@kluyver.me.uk>

File last commit:

r22742:a9028681
r23138:fb70b991
Show More
globalipapp.py
138 lines | 4.6 KiB | text/x-python | PythonLexer
"""Global IPython app to support test running.
We must start our own ipython object and heavily muck with it so that all the
modifications IPython makes to system behavior don't send the doctest machinery
into a fit. This code should be considered a gross hack, but it gets the job
done.
"""
from __future__ import absolute_import
from __future__ import print_function
# Copyright (c) IPython Development Team.
# Distributed under the terms of the Modified BSD License.
import sys
import warnings
from . import tools
from IPython.core import page
from IPython.utils import io
from IPython.utils import py3compat
from IPython.utils.py3compat import builtin_mod
from IPython.terminal.interactiveshell import TerminalInteractiveShell
class StreamProxy(io.IOStream):
"""Proxy for sys.stdout/err. This will request the stream *at call time*
allowing for nose's Capture plugin's redirection of sys.stdout/err.
Parameters
----------
name : str
The name of the stream. This will be requested anew at every call
"""
def __init__(self, name):
warnings.warn("StreamProxy is deprecated and unused as of IPython 5", DeprecationWarning,
stacklevel=2,
)
self.name=name
@property
def stream(self):
return getattr(sys, self.name)
def flush(self):
self.stream.flush()
def get_ipython():
# This will get replaced by the real thing once we start IPython below
return start_ipython()
# A couple of methods to override those in the running IPython to interact
# better with doctest (doctest captures on raw stdout, so we need to direct
# various types of output there otherwise it will miss them).
def xsys(self, cmd):
"""Replace the default system call with a capturing one for doctest.
"""
# We use getoutput, but we need to strip it because pexpect captures
# the trailing newline differently from commands.getoutput
print(self.getoutput(cmd, split=False, depth=1).rstrip(), end='', file=sys.stdout)
sys.stdout.flush()
def _showtraceback(self, etype, evalue, stb):
"""Print the traceback purely on stdout for doctest to capture it.
"""
print(self.InteractiveTB.stb2text(stb), file=sys.stdout)
def start_ipython():
"""Start a global IPython shell, which we need for IPython-specific syntax.
"""
global get_ipython
# This function should only ever run once!
if hasattr(start_ipython, 'already_called'):
return
start_ipython.already_called = True
# Store certain global objects that IPython modifies
_displayhook = sys.displayhook
_excepthook = sys.excepthook
_main = sys.modules.get('__main__')
# Create custom argv and namespaces for our IPython to be test-friendly
config = tools.default_config()
config.TerminalInteractiveShell.simple_prompt = True
# Create and initialize our test-friendly IPython instance.
shell = TerminalInteractiveShell.instance(config=config,
)
# A few more tweaks needed for playing nicely with doctests...
# remove history file
shell.tempfiles.append(config.HistoryManager.hist_file)
# These traps are normally only active for interactive use, set them
# permanently since we'll be mocking interactive sessions.
shell.builtin_trap.activate()
# Modify the IPython system call with one that uses getoutput, so that we
# can capture subcommands and print them to Python's stdout, otherwise the
# doctest machinery would miss them.
shell.system = py3compat.MethodType(xsys, shell)
shell._showtraceback = py3compat.MethodType(_showtraceback, shell)
# IPython is ready, now clean up some global state...
# Deactivate the various python system hooks added by ipython for
# interactive convenience so we don't confuse the doctest system
sys.modules['__main__'] = _main
sys.displayhook = _displayhook
sys.excepthook = _excepthook
# So that ipython magics and aliases can be doctested (they work by making
# a call into a global _ip object). Also make the top-level get_ipython
# now return this without recursively calling here again.
_ip = shell
get_ipython = _ip.get_ipython
builtin_mod._ip = _ip
builtin_mod.get_ipython = get_ipython
# Override paging, so we don't require user interaction during the tests.
def nopage(strng, start=0, screen_lines=0, pager_cmd=None):
if isinstance(strng, dict):
strng = strng.get('text/plain', '')
print(strng)
page.orig_page = page.pager_page
page.pager_page = nopage
return _ip